<?
//start sessions on every page
session_start(); 

//database variables
global $servername;
global $dbname;
global $dbuser;
global $dbpassword;


//system variables
global $website_url;
global $mail_sender;
global $contact_email_adres;
global $website_title_main;
global $website_title;
global $website_keywords;
global $website_description;
global $debug;
global $use_name_urls;
global $quiz_image_location;
global $question_image_location;

$website_title_main = "Quiz-it.nl - Test je kennis met leuke vragen";
$website_title = "Quiz-it.nl";
$website_keywords = "Quiz,quiz,quizzes,quizen,kwiz,kwis,kwissen,kennisquiz,spel,test,iq-test,quizvragen,online,game,vragen,trivia,spel,spelletje,kennis,antwoord,muziek,films,quizmaster,testen,slim,leuk";
$website_description = "De website om je kennis te testen met verschillende quizzes.";

// database variabelen zetten
if ($_SERVER['HTTP_HOST']=="localhost") {
	$servername = "localhost";
	$dbname = "quiz";
	$dbuser = "quiz_user";
	$dbpassword = "qu1z3r";
	$website_url = "http://localhost/xampp/quiz/";
	$debug = false;
	$mail_sender = "alex@halleygroep.nl";
	$contact_email_adres = "alex@halleygroep.nl";
	$use_name_urls = false;
	$quiz_image_location = "images/quiz/";
	$question_image_location = "images/questions/";
}
if ($_SERVER['HTTP_HOST']=="www.quiz-it.nl" || $_SERVER['HTTP_HOST']=="quiz-it.nl") {
	$servername="localhost";
	$dbname="quizit_quiz";
	$dbuser="quizit_user";
	$dbpassword="qu1z3r";
	$website_url = "http://www.quiz-it.nl";
	if ($_SERVER['REMOTE_ADDR']=="212.182.165.155") {
		$debug = false;
	} else {
		$debug = false;
	}
	$mail_sender = "info@quiz-it.nl";
	$contact_email_adres = "info@quiz-it.nl";
	$use_name_urls = true;
	$quiz_image_location = "images/quiz/";
	$question_image_location = "images/questions/";
}
?>
<?
function connecttodb($servername,$dbname,$dbuser,$dbpassword) {
	global $link;
	$link=mysql_connect ("$servername","$dbuser","$dbpassword");
	if(!$link){die("Could not connect to MySQL");}
	mysql_select_db("$dbname",$link) or die ("could not open db: ".mysql_error());
	return $link;
}

function disconnectdb($link) {
	mysql_close($link); 
}
?>
<?
function getNewQuizzesList($count) {
    // geeft een lijst van nieuwe quizzes terug
    $quiz_result = mysql_query("SELECT QIZ_id FROM quizzes WHERE deleted=0 AND active=1 ORDER BY date_created DESC LIMIT $count") or die (mysql_error());
	$quiz_counter = 0;
	while ($row = mysql_fetch_array($quiz_result)) {
		$quiz_list[$quiz_counter] = $row[QIZ_id];
		$quiz_counter++;
	}
	return $quiz_list;
}

function getQuizName($qiz_id) {
	// geeft de naam terug van een quiz
	$quiz_name = "[[geen]]";
	if ($qiz_id!="") {
		$quiz_result = mysql_query("SELECT name FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
		if (mysql_num_rows($quiz_result) > 0) {
			$quiz_name = stripslashes(mysql_result($quiz_result, 0, 'name'));
		}
	}
	return $quiz_name;
}

function getQuizTagDescription($qiz_id) {	
	// geeft de tag_description terug van een quiz
	
	global $website_description;
	
	$tag_description = $website_description;
	if ($qiz_id!="") {
		$category_result = mysql_query("SELECT tag_description FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_description = stripslashes(mysql_result($category_result, 0, 'tag_description'));
		}
	}
	return $tag_description;
}

function getQuizTagKeywords($qiz_id) {	
	// geeft de tag_keywords terug van een quiz
	
	global $website_keywords;
	
	$tag_keywords = $website_keywords;
	if ($qiz_id!="") {
		$category_result = mysql_query("SELECT tag_keywords FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_keywords = stripslashes(mysql_result($category_result, 0, 'tag_keywords'));
		}
	}
	return $tag_keywords;
}

function getQuizDescription($qiz_id) {
	// geeft de omschrijving terug van een quiz
	$quiz_description = "[[geen]]";
	if ($qiz_id!="") {
		$quiz_result = mysql_query("SELECT description FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
		if (mysql_num_rows($quiz_result) > 0) {
			$quiz_description = stripslashes(mysql_result($quiz_result, 0, 'description'));
		}
	}
	return $quiz_description;
}

function getQuizUrl($qiz_id) {
    // geeft de url terug waarop de quiz te vinden is
     
    global $use_name_urls;
    
    if (!$use_name_urls) {
    	$quiz_url = "quiz.php?qiz_id=".$qiz_id;
    } else {
    	$sce_id = getSubCategoryFromQuiz($qiz_id);
    	
    	$quiz_url = getSubCategoryName($sce_id)." ".getQuizName($qiz_id);
		$quiz_url = str_replace(" ","_",$quiz_url);
		$quiz_url = str_replace("/","",$quiz_url);
		$quiz_url = str_replace("'","",$quiz_url);
		$quiz_url = str_replace("(","",$quiz_url);
		$quiz_url = str_replace(")","",$quiz_url);
		$quiz_url = str_replace("&","en",$quiz_url);
		$quiz_url = str_replace("!","",$quiz_url);
		$quiz_url = urlencode(trim(strToLower($quiz_url)));
		$quiz_url .= "_q-".$qiz_id.".html"; 
    }
    return $quiz_url;
}

function getQuizPicture($qiz_id) {
	// geeft het plaatje terug van een quiz
	$quiz_picture = "";
	if ($qiz_id!="") {
		$quiz_result = mysql_query("SELECT picture FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
		if (mysql_num_rows($quiz_result) > 0) {
			$quiz_picture = stripslashes(mysql_result($quiz_result, 0, 'picture'));
		}
	}
	return $quiz_picture;
}

function getPopularQuizzesList($main_categories_count,$quizzes_count) {
    // geeft voor een aantal willekeurige hoofdrubrieken de populairste quizzes terug
    $maincat_result = mysql_query("SELECT MCE_id FROM main_categories WHERE deleted=0 AND active=1 ORDER BY RAND() LIMIT $main_categories_count") or die (mysql_error());
    $maincat_counter = 0;
    while ($catrow = mysql_fetch_array($maincat_result)) {
        $mce_id = $catrow[MCE_id];
        
        $quiz_result = mysql_query("SELECT q.QIZ_id, count(uq.UQZ_id) as nr FROM quizzes q INNER JOIN sub_categories sc ON q.SCE_id=sc.SCE_id INNER JOIN user_quizzes uq ON q.QIZ_id=uq.QIZ_id WHERE q.deleted=0 AND q.active=1 AND sc.MCE_id=$mce_id GROUP BY q.QIZ_id ORDER BY nr DESC") or die (mysql_error());
    	$quiz_counter = 0;
    	while ($row = mysql_fetch_array($quiz_result)) {
    		$quiz_list[$maincat_counter][mce_id] = $mce_id;
    		$quiz_list[$maincat_counter][quizzes][$quiz_counter] = $row[QIZ_id];
    		$quiz_counter++;
    	}
    	$maincat_counter++;
   	}
   	return $quiz_list;
}

function getSubCategoryQuizzesList($sce_id,$nr) {
    // geeft voor een subrubriek de quizzes terug
    if ($nr>0) {
    	$quiz_result = mysql_query("SELECT QIZ_id FROM quizzes WHERE deleted=0 AND active=1 AND SCE_id=$sce_id ORDER BY sequence LIMIT $nr") or die (mysql_error());
    } else {
    	$quiz_result = mysql_query("SELECT QIZ_id FROM quizzes WHERE deleted=0 AND active=1 AND SCE_id=$sce_id ORDER BY sequence") or die (mysql_error());
    }
	$quiz_counter = 0;
	while ($row = mysql_fetch_array($quiz_result)) {
		$quiz_list[$quiz_counter] = $row[QIZ_id];
		$quiz_counter++;
	}
   	return $quiz_list;
}

function getSubCategoryFromQuiz($qiz_id) {
	// geeft de subcategorie terug voor een quiz

	$sub_category_result = mysql_query("SELECT SCE_id FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
	$sce_id = "";
	if (mysql_num_rows($sub_category_result) > 0) $sce_id = mysql_result($sub_category_result, 0, 'SCE_id');
	return $sce_id;
}

function getQuizPickRandomQuestions($qiz_id) {
	// geeft terug of er bij een quiz willekeurige vragen gekozen moeten worden
	$pick_random_questions = 0;
	$quiz_result = mysql_query("SELECT pick_random_questions FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $pick_random_questions = mysql_result($quiz_result, 0, 'pick_random_questions');
	return $pick_random_questions;
}

function getQuizPickRandomQuestionsCount($qiz_id) {
	// geeft terug hoeveel willekeurige vragen er gekozen moeten worden bij een quiz
	$pick_random_questions_count = 10;
	$quiz_result = mysql_query("SELECT pick_random_questions_count FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $pick_random_questions_count = mysql_result($quiz_result, 0, 'pick_random_questions_count');
	return $pick_random_questions_count;
}

function getQuizShuffleQuestions($qiz_id) {
    // geeft terug of de vragen in een quiz door elkaar gehusseld moeten worden
    $shuffle_questions = "";
	$quiz_result = mysql_query("SELECT shuffle_questions FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $shuffle_questions = mysql_result($quiz_result, 0, 'shuffle_questions');
	return $shuffle_questions;
}

function getQuizDifficultyRating($qiz_id) {
    // geeft de moeilijkheidsgraad van een quiz terug
    $difficulty_rating = 0;
	$quiz_result = mysql_query("SELECT difficulty_rating FROM quizzes WHERE QIZ_id=$qiz_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $difficulty_rating = mysql_result($quiz_result, 0, 'difficulty_rating');
	return $difficulty_rating;
}

function displayQuizDifficultyRating($qiz_id) {
	// toont de moeilijkheidgraad van een quiz
	$difficulty_rating = getQuizDifficultyRating($qiz_id);
	
	echo "<table cellpadding=\"0\" cellspacing=\"2\" border=\"0\">";
		echo "<tr>";
			for ($diff_teller=0;$diff_teller<=9;$diff_teller++) {
				$lower_diff = $diff_teller * 10;
				$upper_diff = ($diff_teller+1) * 10;
				echo "<td width=\"10\" height=\"10\">";
					echo "<table cellpadding=\"0\" cellspacing=\"0\" border=\"0\">";
						echo "<tr>";
							if ($difficulty_rating>=$upper_diff) {
								echo "<td bgcolor=\"red\" width=\"10\" height=\"10\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
							} else {
								if ($difficulty_rating<=$lower_diff) {
									echo "<td bgcolor=\"gray\" width=\"10\" height=\"10\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
								} else {
									echo "<td bgcolor=\"red\" width=\"".($difficulty_rating-$lower_diff)."\" height=\"10\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
									echo "<td bgcolor=\"gray\" width=\"".($upper_diff-$difficulty_rating)."\" height=\"10\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
								}
							}
						echo "</tr>";
					echo "</table>";
				echo "</td>";
			}
			echo "<td width=\"5\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
			echo "<td>".(round($difficulty_rating/10,1))."</td>";
		echo "</tr>";
	echo "</table>";	
}

function updateQuizDifficultyRating($qiz_id) {
	// past de moeilijkheidsgraad aan in de database
	// dit wordt berekend uit het gemiddelde van de laatste 3 maanden
	$three_months_ago = date("Y-m-j",mktime(0,0,0,date("m")-3,date("j"),date("Y")));
	
	$diff_result = mysql_query("SELECT Avg(calculated_percentage_correct) as avg_diff FROM user_quizzes WHERE QIZ_id=$qiz_id AND completed=1 AND timestamp_started>'$three_months_ago'") or die (mysql_error());
	if (mysql_num_rows($diff_result) > 0) {
		$avg_diff = mysql_result($diff_result, 0, 'avg_diff');
		$difficulty_rating = round(100 - $avg_diff);
		mysql_query("UPDATE quizzes SET difficulty_rating=$difficulty_rating WHERE QIZ_id=$qiz_id") or die (mysql_error());
	}
}

function getQuizNrOfQuestions($qiz_id) {
	// geeft het aantal vragen terug waaruit de quiz bestaat
	if (getQuizPickRandomQuestions($qiz_id)) {
		$nr_of_questions = getQuizPickRandomQuestionsCount($qiz_id);
	} else {
		$nr_of_questions = count(getQuestionsList($qiz_id));
	}
	return $nr_of_questions;
}

// ################################## weergave quizpaginas ####################################

function displayQuizStart() {
    // toont de startpagina van een quiz
    
    global $quiz_image_location;
    
    $qiz_id = addslashes($_GET['qiz_id']);
    $quiz_name = getQuizName($qiz_id);
    $quiz_description = getQuizDescription($qiz_id);
    $quiz_picture = getQuizPicture($qiz_id);
    $sce_id = getSubCategoryFromQuiz($qiz_id);
    $mce_id = getMainCategoryFromSubCategory($sce_id);
    $subcat_name = getSubCategoryName($sce_id);
    $maincat_name = getMainCategoryName($mce_id);
    $quiz_nr_of_questions = getQuizNrOfQuestions($qiz_id);
    $quiz_pick_random_questions = getQuizPickRandomQuestions($qiz_id);
    
    ?>
    <table cellpadding="0" cellspacing="0" width="738" class="green_bg">
    	<tr>
    		<td>
    			<table cellpadding="0" cellspacing="0" width="734">
    				<tr><td><img src="images/title_quiz_starten.gif" width="165" height="40"></td></tr>
    				<tr>
                       <td align="center">
                            <table cellpadding="0" cellspacing="0" width="706">
                                <tr>
                                    <td width="312" valign="top" align="left">
                                    	<table cellpadding="0" cellspacing="0" width="300">
                                    		<tr><td><img src="<? echo $quiz_image_location; ?>300_200/<? echo $quiz_picture; ?>" width="300" height="200" class="green_image" alt="<? echo $quiz_name; ?>"></td></tr>
                                    		<tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td align="center" class="quiz_nr_of_questions"><? echo $quiz_nr_of_questions." vragen"; ?></td></tr>
                                            <?
                                    		if ($quiz_pick_random_questions) {
                                    			?>
                                    			<tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                           		<tr>
                                    				<td align="center">
                                    					<?
		                                    			echo "Deze vragen worden willekeurig gekozen, dus je krijgt nooit dezelfde quiz!";
		                                    			?>
                                    				</td>
                                            	</tr>
                                    			<?
                                    		} 
                                    		?>                                            
                                    	</table>
                                    </td>
                                    <td width="388" valign="top">
                                        <table cellpadding="0" cellspacing="0" width="388">
                                            <tr><td class="quiz_start_name"><? echo $quiz_name; ?></td></tr>
                                            <tr>
                                                <td>
                                                    <table cellpadding="0" cellspacing="0" width="388">
                                                        <tr>
                                                            <td width="140" class="quiz_start_list">Hoofdcategorie:</td>
                                                            <td width="248" class="quiz_start_list"><? echo $maincat_name; ?></td>
                                                        </tr>
                                                        <tr>
                                                            <td class="quiz_start_list">Subcategorie:</td>
                                                            <td class="quiz_start_list"><? echo $subcat_name; ?></td>
                                                        </tr>
                                                        <tr>
                                                            <td class="quiz_start_list">Moeilijkheidsgraad:</td>
                                                            <td class="quiz_start_list"><? displayQuizDifficultyRating($qiz_id); ?></td>
                                                        </tr>
                                                    </table>
                                                </td>
                                            </tr>
                                            <tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td class="quiz_start_description"><? echo $quiz_description; ?></td></tr>
                                            <tr><td height="10"><img src="images/v.gif" width="1" height="1"></td></tr>
                                            <tr>
                                            	<td height="88" align="center" valign="middle">
                                            		<a href="quiz_doen.php?qiz_id=<? echo $qiz_id; ?>&command=start_quiz#vraag">
                                            			<img src="images/button_klik_hier_om_de_quiz_te_starten.gif" width="247" height="64" border="0" alt="Klik hier om de quiz te starten">
                                            		</a>
                                            	</td>
                                            </tr>
                                        </table>
                                    </td>
                                </tr>
                            </table>
                       </td>
                    </tr>
                    <tr><td height="15"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                    <tr><td align="center"><script type="text/javascript"><!--
google_ad_client = "pub-3519187082459864";
//728x90, gemaakt 11-12-07
google_ad_slot = "6340054995";
google_ad_width = 728;
google_ad_height = 90;
//--></script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script></td></tr>
                    <tr><td height="15"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                </table>
            </td>
        </tr>
    </table>
    <?
}

function displayQuizTopScores() {
	// geeft de topscores lijst weer voor een quiz
	$qiz_id = addslashes($_GET['qiz_id']);
	$usr_id = addslashes($_SESSION['usr_id']);
	if ($qiz_id!="") {
		?>
		<table cellpadding="0" cellspacing="0" width="738" class="green_bg">
			<tr>
				<td>
					<table cellpadding="0" cellspacing="0" width="734">
						<tr><td><img src="images/title_topscores_voor_deze_quiz.gif" width="317" height="40"></td></tr>
						<tr>
		                   <td align="center">
		                   		<table cellpadding="0" cellspacing="0" width="734">
		                   			<tr>
		                   				<td>
					                        <table cellpadding="0" cellspacing="0" width="734">
					                            <tr>
					                            	<td width="366" valign="top" align="center">
					                            		<table border="0" cellpadding="0" cellspacing="0" width="342" class="green_text_nopad">
					                            			<tr>
					                            				<td><b>Hoogste scores vandaag</b></td>
					                            			</tr>
					                            			<tr><td height="5"><img src="images/transpix.gif" width="1" height="1"></td></tr>
					                            			<tr>
					                            				<td>
					                            					<table border="0" cellpadding="0" cellspacing="0" width="342" class="green_text_nopad">
						                            					<?
						                            					$this_year = date("Y");
						                            					$this_month = date("n");
						                            					$this_day = date("j");
						                            					$score_result = mysql_query("SELECT u.USR_id, u.name, uq.calculated_percentage_correct, uq.calculated_time_taken FROM user_quizzes uq INNER JOIN users u ON uq.USR_id=u.USR_id WHERE uq.QIZ_id=$qiz_id AND uq.completed=1 AND (Year(uq.timestamp_started)=$this_year AND Month(uq.timestamp_started)=$this_month AND Day(uq.timestamp_started)>$this_day) AND u.name<>'' ORDER BY uq.calculated_percentage_correct DESC, uq.calculated_time_taken LIMIT 50") or die (mysql_error());
						                            					if (mysql_num_rows($score_result) < 5) $score_result = mysql_query("SELECT u.USR_id, u.name, uq.calculated_percentage_correct, uq.calculated_time_taken FROM user_quizzes uq INNER JOIN users u ON uq.USR_id=u.USR_id WHERE uq.QIZ_id=$qiz_id AND uq.completed=1 AND (Year(uq.timestamp_started)=$this_year AND Month(uq.timestamp_started)=$this_month AND Day(uq.timestamp_started)>($this_day-2)) AND u.name<>'' ORDER BY uq.calculated_percentage_correct DESC, uq.calculated_time_taken LIMIT 50") or die (mysql_error());
																		$score_counter = 1;													
																		while ($row = mysql_fetch_array($score_result)) {
																			$score_user = $row[USR_id];
																			$name = $row[name];
																			$calculated_percentage_correct = $row[calculated_percentage_correct];
																			$calculated_time_taken = $row[calculated_time_taken];
																			
																			$calculated_time_taken_minutes = floor($calculated_time_taken/60);
																			$calculated_time_taken_seconds = $calculated_time_taken - ($calculated_time_taken_minutes*60);
																			if ($calculated_time_taken_seconds<10) $calculated_time_taken_seconds = "0".$calculated_time_taken_seconds;
																			
																			?>
																			<tr>
																				<td height="16"><? echo $score_counter; ?>.</td>
																				<td>
																					<? if ($usr_id==$score_user) { ?>	
																						<a href="jouw_topscores.php?usr_id=<? echo $score_user; ?>"><img src="images/star_yellow.gif" width="16" height="16" alt="Dit is een score van jou! Klik hier voor al jouw topscores" border="0"></a>
																					<? } else { ?>
																						<a href="jouw_topscores.php?usr_id=<? echo $score_user; ?>"><img src="images/user.gif" width="16" height="16" alt="Klik hier voor alle topscores van <? echo $name; ?>" border="0"></a>
																					<? } ?>
																				</td>
																				<td><? echo $name; ?></td>
																				<td><? echo $calculated_percentage_correct; ?>%</td>
																				<td>in</td>
																				<td><? echo $calculated_time_taken_minutes; ?>:<? echo $calculated_time_taken_seconds; ?></td>
																			</tr>
																			<?
																			$score_counter++;
																		}
									                            		?>
									                            	</table>
					                            				</td>
					                            			</tr>
					                            		</table>                            		
					                            	</td>
					                            	<td width="2" class="green_seperator"><img src="images/transpix.gif" width="1" height="1"></td>
					                            	<td width="366" valign="top" align="center">
					                            		<table border="0" cellpadding="0" cellspacing="0" width="342" class="green_text_nopad">
					                            			<tr>
					                            				<td><b>Hoogste scores allertijden</b></td>
					                            			</tr>
					                            			<tr><td height="5"><img src="images/transpix.gif" width="1" height="1"></td></tr>
					                            			<tr>
					                            				<td>
					                            					<table border="0" cellpadding="0" cellspacing="0" width="342" class="green_text_nopad">
						                            					<?
						                            					//$score_result = mysql_query("SELECT u.USR_id, u.name, uq.calculated_percentage_correct, uq.calculated_time_taken FROM user_quizzes uq INNER JOIN users u ON uq.USR_id=u.USR_id WHERE uq.QIZ_id=$qiz_id AND uq.completed=1 AND u.name<>'' ORDER BY uq.calculated_percentage_correct DESC, uq.calculated_time_taken LIMIT 50") or die (mysql_error());
																		$score_result = mysql_query("SELECT u.USR_id, u.name, hs.percentage as calculated_percentage_correct, hs.time_taken as calculated_time_taken FROM user_highscores hs INNER JOIN users u ON hs.USR_id=u.USR_id WHERE hs.QIZ_id=$qiz_id AND u.name<>'' ORDER BY rank LIMIT 50") or die (mysql_error());
																		$score_counter = 1;													
																		while ($row = mysql_fetch_array($score_result)) {
																			$score_user = $row[USR_id];
																			$name = $row[name];
																			$calculated_percentage_correct = $row[calculated_percentage_correct];
																			$calculated_time_taken = $row[calculated_time_taken];
																			
																			$calculated_time_taken_minutes = floor($calculated_time_taken/60);
																			$calculated_time_taken_seconds = $calculated_time_taken - ($calculated_time_taken_minutes*60);
																			if ($calculated_time_taken_seconds<10) $calculated_time_taken_seconds = "0".$calculated_time_taken_seconds;
																			
																			?>
																			<tr>
																				<td height="16"><? echo $score_counter; ?>.</td>
																				<td>
																					<? if ($usr_id==$score_user) { ?>	
																						<a href="jouw_topscores.php?usr_id=<? echo $score_user; ?>"><img src="images/star_yellow.gif" width="16" height="16" alt="Dit is een score van jou! Klik hier voor al jouw topscores" border="0"></a>
																					<? } else { ?>
																						<a href="jouw_topscores.php?usr_id=<? echo $score_user; ?>"><img src="images/user.gif" width="16" height="16" alt="Klik hier voor alle topscores van <? echo $name; ?>" border="0"></a>
																					<? } ?>
																				</td>
																				<td><? echo $name; ?></td>
																				<td><? echo $calculated_percentage_correct; ?>%</td>
																				<td>in</td>
																				<td><? echo $calculated_time_taken_minutes; ?>:<? echo $calculated_time_taken_seconds; ?></td>
																			</tr>
																			<?
																			$score_counter++;
																		}
									                            		?>
									                            	</table>
					                            				</td>
					                            			</tr>
					                            		</table>
					                            	</td>
					                            </tr>
					                        </table>
										</td>
									</tr>									
								</table>
		                    </td>
		                </tr>
		                <tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
		                <tr><td align="center"><script type="text/javascript"><!--
google_ad_client = "pub-3519187082459864";
//728x90, gemaakt 11-12-07
google_ad_slot = "6340054995";
google_ad_width = 728;
google_ad_height = 90;
//--></script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script></td></tr>
                    	<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
		            </table>
		        </td>
		    </tr>
		</table>
		<?
	}
}
?>
<?
function getQuestionsList($qiz_id) {
    // geeft een lijst terug met actieve vragen
    $question_result = mysql_query("SELECT QTN_id FROM questions WHERE QIZ_id=".$qiz_id." AND active=1 ORDER BY sequence") or die (mysql_error());
	$question_counter = 0;
	while ($row = mysql_fetch_array($question_result)) {
		$question_list[$question_counter] = $row[QTN_id];
		$question_counter++;
	}
	return $question_list;
}

function getQuestionText($qtn_id,$cut_off_at) {
	// geeft de tekst terug voor een vraag
	// wanneer cut_off_at groter is dan 0, dan wordt de string op die positie afgebroken
	$question_text = "[[geen]]";
	if ($qtn_id!="") {
		$question_result = mysql_query("SELECT question_text FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
		if (mysql_num_rows($question_result) > 0) {
			$question_text = stripslashes(mysql_result($question_result, 0, 'question_text'));
			if ($cut_off_at>0) {
				if (strlen($question_text)>$cut_off_at) $question_text = substr($question_text,0,$cut_off_at)."...";
			}
		}
	}
	return $question_text;	
}

function getQuestionPicture($qtn_id) {
	// geeft het plaatje terug bij een vraag
	$question_picture = "";
	$question_result = mysql_query("SELECT question_picture FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $question_picture = mysql_result($question_result, 0, 'question_picture');
	return $question_picture;
}

function getQuestionCorrectOTNid($qtn_id) {
	// geeft het correct antwoord terug bij een vraag
	$correct_otn_id = "";
	$question_result = mysql_query("SELECT correct_OTN_id FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $correct_otn_id = mysql_result($question_result, 0, 'correct_OTN_id');
	return $correct_otn_id;
}

function getQuestionPickRandomOptions($qtn_id) {
	// geeft terug of er bij een vraag willekeurige opties gekozen moeten worden
	$pick_random_options = "";
	$question_result = mysql_query("SELECT pick_random_options FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $pick_random_options = mysql_result($question_result, 0, 'pick_random_options');
	return $pick_random_options;
}

function getQuestionPickRandomOptionsCount($qtn_id) {
	// geeft terug hoeveel willekeurige opties er gekozen moeten worden bij een vraag
	$pick_random_options_count = 4;
	$question_result = mysql_query("SELECT pick_random_options_count FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $pick_random_options_count = mysql_result($question_result, 0, 'pick_random_options_count');
	return $pick_random_options_count;
}

function getQuestionShuffleOptions($qtn_id) {
	// geeft terug of bij een vraag de opties geshuffled moeten worden
	$shuffle_options = 1;
	$question_result = mysql_query("SELECT shuffle_options FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $shuffle_options = mysql_result($question_result, 0, 'shuffle_options');
	if ($shuffle_options==1) {
		$shuffle_options = true;
	} else {
		$shuffle_options = false;
	}
	return $shuffle_options;
}

function getQuestionUseOptionLetters($qtn_id) {
	// geeft terug of bij een vraag de opties geshuffled moeten worden
	$use_option_letters = 1;
	$question_result = mysql_query("SELECT use_option_letters FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $use_option_letters = mysql_result($question_result, 0, 'use_option_letters');
	if ($use_option_letters==1) {
		$use_option_letters = true;
	} else {
		$use_option_letters = false;
	}
	return $use_option_letters;
}

function getQuestionQuiz($qtn_id) {
	// geeft de quiz terug bij een vraag
	$qiz_id = "";
	$question_result = mysql_query("SELECT QIZ_id FROM questions WHERE QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($question_result) > 0) $qiz_id = mysql_result($question_result, 0, 'QIZ_id');
	return $qiz_id;
}

// ##################################### opties ################################

function getOptionsList($qtn_id,$exclude_otn_id) {
	// geeft een lijst terug met opties
	$option_result = mysql_query("SELECT OTN_id FROM options WHERE QTN_id=".$qtn_id." AND OTN_id <> $exclude_otn_id") or die (mysql_error());
	$option_counter = 0;
    while ($row = mysql_fetch_array($option_result)) {
		$option_list[$option_counter] = $row[OTN_id];
	   	$option_counter++;
   	}
    return $option_list;
}

function getQuestionOptionsList($qtn_id) {	
	// geeft een lijstje met opties terug voor bij een vraag
	global $debug;
	
	$shuffle_options = getQuestionShuffleOptions($qtn_id);
	
	if ($shuffle_options) {
		// opties shuffelen
		$correct_otn_id = getQuestionCorrectOTNid($qtn_id);
		if ($debug) echo "correct: $correct_otn_id <BR>";
		$options_list = getOptionsList($qtn_id,$correct_otn_id);
		if ($debug) {
			print_r($options_list);
			echo "<BR><BR>";
		}
		shuffle($options_list);
		if ($debug) {
			print_r($options_list);
			echo "<BR><BR>";
		}
		
		$pick_random_options = getQuestionPickRandomOptions($qtn_id);
		$pick_random_options_count = getQuestionPickRandomOptionsCount($qtn_id);
		if ($pick_random_options) {
			$new_options_list[0] = $correct_otn_id;
			for ($teller=1;$teller<$pick_random_options_count;$teller++) {
				$new_options_list[$teller] = $options_list[$teller-1];
			}
		} else {
			$new_options_list[0] = $correct_otn_id;
			for ($teller=1;$teller<=count($options_list);$teller++) {
				$new_options_list[$teller] = $options_list[$teller-1];
			}
		}
		if ($debug) {
			print_r($new_options_list);
			echo "<BR><BR>";
		}
		shuffle($new_options_list);
		if ($debug) {
			print_r($new_options_list);
			echo "<BR><BR>";
		}
	} else {
		// opties niet shuffelen
		$new_options_list = getOptionsList($qtn_id,0);
		if ($debug) {
			print_r($new_options_list);
			echo "<BR><BR>";
		}
	}
	return $new_options_list;
}

function getOptionText($otn_id,$cut_off_at) {
	// geeft de tekst terug voor een optie
	// wanneer cut_off_at groter is dan 0, dan wordt de string op die positie afgebroken
	$option_text = "[[geen]]";
	if ($otn_id!="") {
		$option_result = mysql_query("SELECT option_text FROM options WHERE OTN_id=$otn_id") or die (mysql_error());
		if (mysql_num_rows($option_result) > 0) {
			$option_text = stripslashes(mysql_result($option_result, 0, 'option_text'));
			if ($cut_off_at>0) {
				if (strlen($option_text)>$cut_off_at) $option_text = substr($option_text,0,$cur_off_at)."...";
			}
		}
	}
	return $option_text;
}

function getOptionPicture($otn_id) {
	// geeft het plaatje terug bij eenoptie
	$option_picture = "";
	$option_result = mysql_query("SELECT option_picture FROM options WHERE OTN_id=$otn_id") or die (mysql_error());
	if (mysql_num_rows($option_result) > 0) $option_picture = mysql_result($option_result, 0, 'option_picture');
	return $option_picture;
}
?><?
function makeUserQuiz() {
	// samenstellen van nieuwe vragenlijst voor een quiz voor een gebruiker
	
	global $debug;
	
	$usr_id = addslashes($_SESSION['usr_id']);
	$qiz_id = addslashes($_GET['qiz_id']);
	
	// quiz-waarden ophalen
	$shuffle_questions = getQuizShuffleQuestions($qiz_id);
	$quiz_pick_random_questions = getQuizPickRandomQuestions($qiz_id);
	$quiz_nr_of_questions = getQuizNrOfQuestions($qiz_id);
	
	// weghalen oudere versies
	// weggehaald vanwege overbelasting op server
	// clearOlderUsersNotActive();
	// clearOlderUserQuizzesNotCompleted();
	
	// ophalen alle vragen voor deze quiz
	$all_questions_list = getQuestionsList($qiz_id);	
	if ($debug) {
		print_r($all_questions_list);
		echo "<BR><BR>";
	}
	
	// toevoegen gebruikersquiz
	$timestamp_started = date("Y-m-j H:i:s",mktime(date("H"),date("i"),date("s"),date("m"),date("j"),date("Y")));
	mysql_query("INSERT INTO user_quizzes (USR_id,QIZ_id,timestamp_started) VALUES ($usr_id,$qiz_id,'$timestamp_started')") or die (mysql_error());
	$uqz_id = mysql_insert_id();
	$_SESSION['uqz_id'] = $uqz_id;
	
	// eventueel vragen huzzelen
	if ($shuffle_questions || $quiz_pick_random_questions) {
		shuffle($all_questions_list);
		if ($debug) {
			print_r($all_questions_list);
			echo "<BR><BR>";
		}
	}
	
	// door de vragen in de lijst heen lopen tot het aantal vragen bereikt is
	for ($teller=0;$teller < $quiz_nr_of_questions;$teller++) {
		if ($teller < count($all_questions_list)) {
			$qtn_id = $all_questions_list[$teller];			
			$sequence = $teller + 1;
			mysql_query("INSERT INTO user_quiz_answers (UQZ_id,QTN_id,sequence) VALUES ($uqz_id,$qtn_id,$sequence)") or die (mysql_error());
		} 		
	}
}

function clearOlderUserQuizzesNotCompleted() {
	// verwijdert gebruikeresquizzes en vragen die al 2 dagen niet gecomplete zijn
	$this_month = date("n");	
	$this_day = date("j")-1;	
	mysql_query("DELETE FROM user_quizzes WHERE completed=0 AND (Month(timestamp_started)<>$this_month OR (Month(timestamp_started)=$this_month AND Day(timestamp_started)<$this_day))") or die (mysql_error());
	mysql_query("DELETE FROM user_quiz_answers WHERE UQZ_id NOT IN (SELECT UQZ_id FROM user_quizzes)") or die (mysql_error());
}

function getNextUserQuizQuestion($uqz_id) {
	// geeft de eerstvolgende vraag van een gebruikersquiz terug die nog niet beantwoord is
	$qtn_id = "";
	$quiz_result = mysql_query("SELECT QTN_id FROM user_quiz_answers WHERE UQZ_id=$uqz_id AND OTN_id=0 ORDER BY sequence LIMIT 1") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $qtn_id = mysql_result($quiz_result, 0, 'QTN_id');
	return $qtn_id;
}

function getUserQuizQuiz($uqz_id) {
	// geeft de quiz terug van een gebruikersquiz
	$qiz_id = 0;
	$quiz_result = mysql_query("SELECT QIZ_id FROM user_quizzes WHERE UQZ_id=$uqz_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $qiz_id = mysql_result($quiz_result, 0, 'QIZ_id');
	return $qiz_id;
}

function displayUserQuizQuestion() {
	// geeft een quizvraag weer voor een gebruikersquiz
	
	global $debug;
	global $question_image_location;
	
	$usr_id = addslashes($_SESSION['usr_id']);
	$uqz_id = addslashes($_SESSION['uqz_id']);
	$qiz_id = getUserQuizQuiz($uqz_id);
	$quiz_name = getQuizName($qiz_id);
	
	// eerst bepalen welke vraag er getoond moet worden
	$qtn_id = getNextUserQuizQuestion($uqz_id);
	if ($debug) echo "vraag qtn_id: $qtn_id <BR>";
	
	// ophalen aantal vragen 
	$quiz_nr_of_questions = getQuizNrOfQuestions($qiz_id);
	// ophalen huidige vraag nr
	$question_sequence = getUserQuizAnswerSequence($uqz_id,$qtn_id);
	
	?>
	<script language="javascript">
		function mouseOverOption(current_option) {
			eval(current_option).className = 'quiz_option_hover';
		}
		function mouseOutOption(current_option) {
			eval(current_option).className = '';
		}
		function mouseClick(qtn_id,otn_id) {
			document.location.href = 'quiz_doen.php?command=pick_option&qtn_id='+qtn_id+'&otn_id='+otn_id+'#vraag';
		}
	</script>
	<a name="question"></a>
	<table cellpadding="0" cellspacing="0" width="606" border="0">
		<tr>
			<td>
				<table cellpadding="0" cellspacing="0" width="602" class="quiz_top_table">
			    	<tr>
			    		<td>
			    			<table cellpadding="0" cellspacing="0" width="592" class="quiz_top_content">
			    				<tr>
			    					<td>Quiz: <? echo $quiz_name; ?></td>
			    					<td align="right">Vraag <? echo $question_sequence; ?>/<? echo $quiz_nr_of_questions; ?></td>
			    				</tr>
			    			</table>
			    		</td>
			    	</tr>
			    </table>
			</td>
		</tr>
		<?
		$question_text = getQuestionText($qtn_id,0);
		$question_picture = getQuestionPicture($qtn_id);
		if ($question_text!="") {
			?>
			<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
			<tr>
				<td align="center" class="quiz_question"><? echo $question_text; ?></td>
			</tr>
			<?
		}
		if ($question_picture!="") {
			$picture_width = 1;
			$picture_height = 1;
			if (file_exists("images/questions/".$question_picture)) list($picture_width, $picture_height) = getimagesize("images/questions/".$question_picture);
			?>
			<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
			<tr>
				<?
				echo "<td align=\"center\">";
					echo "<img src=\"".$question_image_location.$question_picture."\" width=\"".$picture_width."\" height=\"".$picture_height."\" class=\"quiz_question_image\" border=\"0\" alt=\"".$question_text."\">";
				echo "</td>";
				?>				
			</tr>
			<?
		}		
		$options_list = getQuestionOptionsList($qtn_id);
		$use_option_letters = getQuestionUseOptionLetters($qtn_id);
		if (count($options_list)>0) {
			?>
			<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
			<tr>
				<td align="center">
					<table cellpadding="0" cellspacing="0" class="quiz_options">
						<?
						for ($teller=0;$teller<count($options_list);$teller++) {
							$otn_id = $options_list[$teller];
							$option_text = getOptionText($otn_id,0);
							$option_picture = getOptionPicture($otn_id);
							?>
							<tr>
								<td id="option_square_<? echo $teller; ?>" onMouseOver="javascript:mouseOverOption('option_square_<? echo $teller; ?>');" onMouseOut="javascript:mouseOutOption('option_square_<? echo $teller; ?>');" onClick="javascript:mouseClick(<? echo $qtn_id; ?>,<? echo $otn_id; ?>);">
									<table cellpadding="0" cellspacing="0" border="0">
										<tr>
											<td width="40" class="quiz_option_letter"><? if ($use_option_letters) { echo chr(65+$teller); } else { echo "&nbsp;"; } ?></td>
											<td class="quiz_option_text"><? echo $option_text; ?></td>
											<td width="40"><img src="images/transpix.gif" width="1" height="1"></td>
										</tr>
									</table>
								</td>
							</tr>
							<?
						}
						?>
					</table>
				</td>
			</tr>
			<?
		}
		?>
	</table>
	<?	
}

function answerUserQuizQuestion() {
	// selecteert een optie bij een gebruikersquiz
	
	global $debug;
	
	$usr_id = addslashes($_SESSION['usr_id']);
	$uqz_id = addslashes($_SESSION['uqz_id']);	
	$qtn_id = addslashes($_GET['qtn_id']);
	$otn_id = addslashes($_GET['otn_id']);
	
	$correct_otn_id = getQuestionCorrectOTNid($qtn_id);
	$calculated_correct = 0;
	if ($otn_id==$correct_otn_id) $calculated_correct = 1;
	
	if ($uqz_id!="") {
		mysql_query("UPDATE user_quiz_answers SET OTN_id=$otn_id, calculated_correct=$calculated_correct WHERE UQZ_id=$uqz_id AND QTN_id=$qtn_id") or die (mysql_error());
	}
}

function getUserQuizScore($uqz_id) {
	// geeft de score op een quiz terug voor een gebruiker
	$score = array();
	$userquiz_result = mysql_query("SELECT * FROM user_quizzes WHERE UQZ_id=$uqz_id") or die (mysql_error());
	if (mysql_num_rows($userquiz_result) > 0) {
		$score[calculated_time_taken] = mysql_result($userquiz_result, 0, 'calculated_time_taken');
		$score[calculated_nr_of_questions] = mysql_result($userquiz_result, 0, 'calculated_nr_of_questions');
		$score[calculated_nr_of_answers_correct] = mysql_result($userquiz_result, 0, 'calculated_nr_of_answers_correct');
		$score[calculated_percentage_correct] = mysql_result($userquiz_result, 0, 'calculated_percentage_correct');
	}
	return $score;
}

// ################################## quiz antwoorden ###################################3

function getUserQuizAnswerSequence($uqz_id,$qtn_id) {
	// geeft het volgnummer van een quizvraag terug
	$sequence = 0;
	$quiz_result = mysql_query("SELECT sequence FROM user_quiz_answers WHERE UQZ_id=$uqz_id AND QTN_id=$qtn_id") or die (mysql_error());
	if (mysql_num_rows($quiz_result) > 0) $sequence = mysql_result($quiz_result, 0, 'sequence');
	return $sequence;
}

function finishUserQuiz() {
	// verwerken eindresultaten na afloop van quiz
	
	global $debug;
	
	$uqz_id = addslashes($_SESSION['uqz_id']);
	$timestamp_ended = mktime(date("H"),date("i"),date("s"),date("m"),date("j"),date("Y"));
	
	$userquiz_result = mysql_query("SELECT timestamp_started FROM user_quizzes WHERE UQZ_id=$uqz_id") or die (mysql_error());
	if (mysql_num_rows($userquiz_result) > 0) {
		$timestamp_started = strtotime(mysql_result($userquiz_result, 0, 'timestamp_started'));
		if ($debug) echo "start: ".$timestamp_started."<BR>";
		if ($debug) echo "eind: ".$timestamp_ended."<BR>";
		$calculated_time_taken = $timestamp_ended - $timestamp_started;
		if ($debug) echo "tijd: ".$calculated_time_taken."<BR>";
		
		$userquizanswers_result = mysql_query("SELECT Sum(calculated_correct) as correct, Count(QTN_id) as total FROM user_quiz_answers WHERE UQZ_id=$uqz_id") or die (mysql_error());
		if (mysql_num_rows($userquizanswers_result) > 0) {
			$calculated_nr_of_questions = mysql_result($userquizanswers_result, 0, 'total');		
			$calculated_nr_of_answers_correct = mysql_result($userquizanswers_result, 0, 'correct');		
			$calculated_percentage_correct = 0;
			if ($calculated_nr_of_questions>0) $calculated_percentage_correct = round(($calculated_nr_of_answers_correct / $calculated_nr_of_questions)*100);
			
			if ($debug) echo "calculated_nr_of_questions: ".$calculated_nr_of_questions."<BR>";
			if ($debug) echo "calculated_nr_of_answers_correct: ".$calculated_nr_of_answers_correct."<BR>";
			
			mysql_query("UPDATE user_quizzes SET timestamp_ended='$timestamp_ended', calculated_time_taken=$calculated_time_taken, completed=1, calculated_nr_of_questions=$calculated_nr_of_questions, calculated_nr_of_answers_correct=$calculated_nr_of_answers_correct, calculated_percentage_correct=$calculated_percentage_correct WHERE UQZ_id=$uqz_id") or die (mysql_error());
			
			$usr_id = addslashes($_SESSION['usr_id']);
			$qiz_id = getUserQuizQuiz($uqz_id);
			updateUserHighScore($usr_id,$qiz_id);
		}
	}
}

function getUserAnswersList($uqz_id) {
	// geeft een lijstje terug met de antwoorden van een gebruiker op een quiz
	$answer_result = mysql_query("SELECT * FROM user_quiz_answers WHERE UQZ_id=".$uqz_id." ORDER BY sequence") or die (mysql_error());
	$answer_counter = 0;
	while ($row = mysql_fetch_array($answer_result)) {
		$answer_list[$answer_counter][QTN_id] = $row[QTN_id];
		$answer_list[$answer_counter][OTN_id] = $row[OTN_id];
		$answer_counter++;
	}
	return $answer_list;
}

function displayUserQuizFinish() {
	// geeft de resultaatpagina weer na afloop van een quiz
	
	$usr_id = addslashes($_SESSION['usr_id']);
	$uqz_id = addslashes($_SESSION['uqz_id']);
	$qiz_id = getUserQuizQuiz($uqz_id);
	
	$quiz_name = getQuizName($qiz_id);
	$quiz_pick_random_questions = getQuizPickRandomQuestions($qiz_id);
	$userquiz_score = getUserQuizScore($uqz_id);
	
	$calculated_time_taken = $userquiz_score[calculated_time_taken];
	$calculated_time_taken_minutes = floor($calculated_time_taken/60);
	$calculated_time_taken_seconds = $calculated_time_taken - ($calculated_time_taken_minutes*60);
	?>
    <table cellpadding="0" cellspacing="0" width="738" class="green_bg">
    	<tr>
    		<td>
    			<table cellpadding="0" cellspacing="0" width="734">
    				<tr><td><img src="images/title_quizresultaat.gif" width="185" height="40"></td></tr>
    				<tr>
                       <td align="center">
                            <table cellpadding="0" cellspacing="0" width="706">
                                <tr>
                                    <td width="540" valign="top" align="left">
                                    	<table border="0" cellpadding="0" cellspacing="0" width="540">
                                            <tr><td class="quiz_start_name"><? echo $quiz_name; ?></td></tr>
                                            <tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td class="quiz_result_score">Jouw score: <? echo $userquiz_score[calculated_nr_of_answers_correct]; ?>/<? echo $userquiz_score[calculated_nr_of_questions]; ?> (<? echo $userquiz_score[calculated_percentage_correct]; ?>%)</td></tr>
                                            <tr><td class="quiz_result_time">Jouw tijd: <? echo $calculated_time_taken_minutes; ?> minuten en <? echo $calculated_time_taken_seconds; ?> seconden</td></tr>
                                            <tr><td height="15"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr>
                                            	<td class="quiz_result_text">
                                            		<?
                                            		$user_name = getUserName($usr_id);
                                            		if ($user_name=="") {
                                            			?>                                            			
                                            			<table border="0" cellpadding="0" cellspacing="0" class="quiz_result_text">
                                            				<form method="post" name="username_form" action="quiz.php?command=enter_user_name&qiz_id=<? echo $qiz_id; ?>">
                                            				<script language="javascript">
                                            					function checkUserName() {
                                            						msg = '';
                                            						username = document.username_form.name.value;
                                            						if (username.length > 15) msg = 'Naam is te lang (max 15 tekens)';
                                            						if (username=='') msg = 'Naam is niet ingevuld';
                                            						if (msg == '') {
                                            							document.username_form.submit();
                                            						} else {
                                            							alert(msg);
                                            						}
                                            					}
                                            				</script>
                                            				<tr><td colspan="5" height="24">Vul je naam in om aan de topscorelijst toegevoegd te worden.</td></tr>
                                            				<tr>
                                            					<td>Jouw naam:</td>
                                            					<td width="5"><img src="images/transpix.gif" width="1" height="1"></td>
                                            					<td><input type="text" name="name" value="" maxlength="15"></td>
                                            					<td width="5"><img src="images/transpix.gif" width="1" height="1"></td>
                                            					<td><a href="javascript:checkUserName();"><img src="images/button_ok.gif" width="50" height="24" border="0"></a></td>
                                            				</tr>
                                            				</form>
                                            			</table>
                                            			<?
                                            		} else {
                                            			?>
                                            			Je score is toegevoegd aan de topscorelijst onder de naam '<? echo $user_name; ?>'.<BR>
                                            			Klik <a href="quiz.php?command=topscores&qiz_id=<? echo $qiz_id; ?>" class="green_link">hier</a> om naar de topscorelijst toe te gaan.
                                            			<?                                            			
                                            		}
                                            		?>
                                            	</td>
                                            </tr>
                                            <tr><td height="15"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td height="2" class="green_seperator"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr>
                                            	<td>
                                            		<?
                                            		$answers_list = getUserAnswersList($uqz_id);
                                            		if (count($answers_list)>0) {
                                            			$column_counter = 0;
                                            			?>
                                            			<table border="0" cellpadding="0" cellspacing="0" width="540">
                                            				<?
                                            				for ($answer_counter=0;$answer_counter<count($answers_list);$answer_counter++) {
                                            					if ($column_counter==0) {
                                            						echo "<tr>";
                                            					}
                                            					
                                            					echo "<td width=\"180\" valign=\"top\" align=\"center\">";
                                            						displayUserQuizAnswer($answer_counter+1,$answers_list[$answer_counter][QTN_id],$answers_list[$answer_counter][OTN_id]);
                                            					echo "</td>";
                                            					
                                            					$column_counter++;
                                            					if ($column_counter==3) {
                                            						echo "</tr><tr><td colspan=\"3\" height=\"10\"><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td></tr>";
                                            						$column_counter=0;
                                            					}
                                            				}
                                            				if ($column_counter>0) {
                                            					for ($teller=$column_counter;$teller<3;$teller++) {
                                            						echo "<td><img src=\"images/transpix.gif\" width=\"1\" height=\"1\"></td>";
                                            					}
                                            				}                                          				
                                            				?>
                                            			</table>
                                            			<?
                                            		}
                                            		?>
                                            	</td>
                                            </tr>
                                            <tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td height="2" class="green_seperator"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                            <tr><td height="30"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                                           	<tr>
                                            	<td>
			                                    	<a href="quiz.php?qiz_id=<? echo $qiz_id; ?>&command=start_quiz">
			                                			<img src="images/button_quiz_opnieuw_starten.gif" width="247" height="64" border="0" alt="Klik hier om de quiz opnieuw te starten">
			                                		</a>                                                                           	
			                                	</td>
			                                </tr>
			                            </table>
                                    </td>    
                                    <td width="12"><img src="images/transpix.gif" width="1" height="1"></td>
                                    <td width="154" valign="top" align="left">
                                    	<table border="0" cellpadding="0" cellspacing="0" width="154">
                                    		<tr>
                                    			<td>
			                                    	<table border="0" cellpadding="0" cellspacing="0" width="154" class="quiz_history">
			                                    		<tr><td colspan="2" class="quiz_history_title">Jouw Top 10:</td></tr>
				                                    	<?
				                                    	$history_counter = 0;
				                                    	$history_result = mysql_query("SELECT * FROM user_quizzes WHERE USR_id=".$usr_id." AND QIZ_id=".$qiz_id." AND completed=1 ORDER BY calculated_percentage_correct DESC, calculated_time_taken DESC LIMIT 10") or die (mysql_error());
														while ($row = mysql_fetch_array($history_result)) {
															$list_uqz_id = $row[UQZ_id];
															$calculated_percentage_correct = $row[calculated_percentage_correct];
															$calculated_time_taken = $row[calculated_time_taken];
															$calculated_time_taken_minutes = floor($calculated_time_taken/60);
															$calculated_time_taken_seconds = $calculated_time_taken - ($calculated_time_taken_minutes*60);
															if ($calculated_time_taken_seconds<10) $calculated_time_taken_seconds = "0".$calculated_time_taken_seconds;
															
															if ($uqz_id==$list_uqz_id) {
																$class = "quiz_history_current";
															} else {
																$class = "quiz_history";
															}
															?>
															<tr>
																<td width="60" class="<? echo $class; ?>">
																	<? echo $calculated_percentage_correct; ?>%
																</td>
																<td width="94" align="right" class="<? echo $class; ?>">
																	in <? echo $calculated_time_taken_minutes.":".$calculated_time_taken_seconds; ?>
																</td>
															</tr>
															<?
															$history_counter++;
														}
														?>
													</table>
												</td>
											</tr>
											<tr><td height="20"><img src="images/transpix.gif" width="1" height="1"></td></tr>
											<tr>
												<td>
													<?
													if ($history_counter>1) {
														?>
														<table border="0" cellpadding="0" cellspacing="0" width="154" class="quiz_history">
															<tr><td colspan="2" class="quiz_history_title">Jouw Gemiddelde:</td></tr>
				                                    		<?
				                                    		$history_avg_result = mysql_query("SELECT Avg(calculated_percentage_correct) as avg_percentage, Avg(calculated_time_taken) as avg_time_taken FROM user_quizzes WHERE USR_id=".$usr_id." AND QIZ_id=".$qiz_id." AND completed=1") or die (mysql_error());
															while ($row = mysql_fetch_array($history_avg_result)) {
																$list_uqz_id = $row[UQZ_id];
																$avg_percentage = round($row[avg_percentage]);
																$avg_time_taken = round($row[avg_time_taken]);
																
																$avg_time_taken_minutes = floor($avg_time_taken/60);
																$avg_time_taken_seconds = $avg_time_taken - ($avg_time_taken_minutes*60);
																if ($avg_time_taken_seconds<10) $avg_time_taken_seconds = "0".$avg_time_taken_seconds;
																?>
																<tr>
																	<td width="60">
																		<? echo $avg_percentage; ?>%
																	</td>
																	<td width="94" align="right">
																		in <? echo $avg_time_taken_minutes.":".$avg_time_taken_seconds; ?>
																	</td>
																</tr>
																<?
															}
															?>
														</table>
														<?
													}
			                                    	?>	 
			                                    </td>
			                        		</tr>
			                        	</table>                                 
                                    </td>                                
                                </tr>
                            </table>
                       </td>
                    </tr>
                    <tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                </table>
            </td>
        </tr>
    </table>
    <?
    $_SESSION['uqz_id'] = "";
    updateQuizDifficultyRating($qiz_id);
}

function displayUserQuizAnswer($question_nr,$qtn_id,$selected_otn_id) {
	// geeft 1 vraag, gekozen antwoord en correcte antwoord weer
	
	global $question_image_location;
	
	$question_text = getQuestionText($qtn_id,0);
	$question_picture = getQuestionPicture($qtn_id);
	$correct_otn_id = getQuestionCorrectOTNid($qtn_id);
	
	$selected_otn_text = getOptionText($selected_otn_id,0);
	$correct_otn_text = getOptionText($correct_otn_id,0);
	?>
	<table border="0" cellpadding="0" cellspacing="0" width="170">
		<tr><td align="center" class="result_answer_question">Vraag <? echo $question_nr; ?>: <? echo $question_text; ?></td></tr>
		<tr><td height="5"><img src="images/transpix.gif" width="1" height="1"></td></tr>
		<? if ($question_picture!="") { ?>
			<tr><td align="center"><img src="<? echo $question_image_location; ?>120_80/<? echo $question_picture; ?>" width="120" height="80" alt="Vraag: <? echo $question_nr; ?>" class="result_answer_image"></td></tr>
			
		<? } ?>
		<? if ($selected_otn_id==$correct_otn_id) { ?>
			<tr><td class="result_option_correct"><? echo $correct_otn_text; ?></td></tr>
		<? } else { ?>
			<tr><td class="result_option_incorrect"><? echo $selected_otn_text; ?></td></tr>
			<tr><td class="result_option_correct"><? echo $correct_otn_text; ?></td></tr>
		<? } ?>
	</table>
	<?
}

function enterUserName() {
	// pagina na het invoeren van gebruikersnaam
	?>
	<table cellpadding="0" cellspacing="0" width="738" class="green_bg">
    	<tr>
    		<td>
    			<table cellpadding="0" cellspacing="0" width="734">
    				<tr><td><img src="images/title_topscores.gif" width="136" height="40"></td></tr>
    				<tr>
                       <td align="center">
                            <table cellpadding="0" cellspacing="0" width="706">
                                <tr>
                                	<td width="706">
                                		<?
                                		$usr_id = addslashes($_SESSION['usr_id']);
                                		$qiz_id = addslashes($_GET['qiz_id']);
                                		$name = addslashes($_POST['name']);
                                		$name = str_replace("<","",$name);
                                		$name = str_replace(">","",$name);
                                		mysql_query("UPDATE users SET name='$name' WHERE USR_id=$usr_id") or die (mysql_error());
                                		?>
                                		<BR>
                                		Je score is opgeslagen in de topscorelijst.<BR>
                                		<BR>
                                		<BR>
                                		Klik <a href="quiz.php?qiz_id=<? echo $qiz_id; ?>" class="green_link">hier</a> om te proberen je score op deze quiz te verbeteren.<BR>
                                		<BR>
                                		Klik <a href="quiz.php?command=topscores&qiz_id=<? echo $qiz_id; ?>" class="green_link">hier</a> om de topscorelijst te bekijken.<BR>
                                	</td>
                                </tr>
                            </table>
                        </td>
                    </tr>
                 	<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
                </table>
            </td>
        </tr>
    </table>
    <?
}
?><?
function getMainCategoriesList() {
	// geeft een lijst terug met hoofdcategorieen
	$main_category_result = mysql_query("SELECT MCE_id FROM main_categories WHERE deleted=0 AND active=1 ORDER BY sequence") or die (mysql_error());
	$main_category_counter = 0;
	while ($row = mysql_fetch_array($main_category_result)) {
		$main_category_list[$main_category_counter] = $row[MCE_id];
		$main_category_counter++;
	}
	return $main_category_list;
}

function getMainCategoryName($mce_id) {
	// geeft de naam terug van een hoofdcategorie
	$category_name = "[[geen]]";
	if ($mce_id!="") {
		$category_result = mysql_query("SELECT name FROM main_categories WHERE MCE_id=$mce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$category_name = stripslashes(mysql_result($category_result, 0, 'name'));
		}
	}
	return $category_name;
}

function getMainCategoryTagDescription($mce_id) {	
	// geeft de tag_description terug van een hoofdcategorie
	
	global $website_description;
	
	$tag_description = $website_description;
	if ($mce_id!="") {
		$category_result = mysql_query("SELECT tag_description FROM main_categories WHERE MCE_id=$mce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_description = stripslashes(mysql_result($category_result, 0, 'tag_description'));
		}
	}
	return $tag_description;
}

function getMainCategoryTagKeywords($mce_id) {	
	// geeft de tag_keywords terug van een hoofdcategorie
	
	global $website_keywords;
	
	$tag_keywords = $website_keywords;
	if ($mce_id!="") {
		$category_result = mysql_query("SELECT tag_keywords FROM main_categories WHERE MCE_id=$mce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_keywords = stripslashes(mysql_result($category_result, 0, 'tag_keywords'));
		}
	}
	return $tag_keywords;
}

function getMainCategoryDescription($mce_id) {
	// geeft de omschrijving terug van een hoofdcategorie
	$category_description = "";
	if ($mce_id!="") {
		$category_result = mysql_query("SELECT description FROM main_categories WHERE MCE_id=$mce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$category_description = stripslashes(mysql_result($category_result, 0, 'description'));
		}
	}
	return $category_description;
}

function getMainCategoryUrl($mce_id) {
    // geeft de url terug waarop de hoofdcategorie te vinden is
    
    global $use_name_urls;
    
    if (!$use_name_urls) {
    	$maincat_url = "hoofdcategorie.php?mce_id=".$mce_id;
    } else {
    	$maincat_url = getMainCategoryName($mce_id);
		$maincat_url = str_replace(" ","_",$maincat_url);
		$maincat_url = str_replace("/","",$maincat_url);
		$maincat_url = str_replace("'","",$maincat_url);
		$maincat_url = str_replace("(","",$maincat_url);
		$maincat_url = str_replace(")","",$maincat_url);
		$maincat_url = str_replace("&","en",$maincat_url);
		$maincat_url = str_replace("!","",$maincat_url);
		$maincat_url = urlencode(trim(strToLower($maincat_url)));
		$maincat_url .= "_m-".$mce_id.".html"; 
    }
    return $maincat_url;
}
?>
<?
function getSubCategoriesList($mce_id) {
	// geeft een lijst terug met subcategorieen
	$sub_category_result = mysql_query("SELECT SCE_id FROM sub_categories WHERE deleted=0 AND active=1 AND MCE_id=".$mce_id." ORDER BY sequence") or die (mysql_error());
	$sub_category_counter = 0;
	while ($row = mysql_fetch_array($sub_category_result)) {
		$sub_category_list[$sub_category_counter] = $row[SCE_id];
		$sub_category_counter++;
	}
	return $sub_category_list;
}

function getSubCategoryName($sce_id) {
	// geeft de naam terug van een subcategorie
	$category_name = "[[geen]]";
	if ($sce_id!="") {
		$category_result = mysql_query("SELECT name FROM sub_categories WHERE SCE_id=$sce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$category_name = stripslashes(mysql_result($category_result, 0, 'name'));
		}
	}
	return $category_name;
}

function getSubCategoryTagDescription($sce_id) {	
	// geeft de tag_description terug van een subcategorie
	
	global $website_description;
	
	$tag_description = $website_description;
	if ($sce_id!="") {
		$category_result = mysql_query("SELECT tag_description FROM sub_categories WHERE SCE_id=$sce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_description = stripslashes(mysql_result($category_result, 0, 'tag_description'));
		}
	}
	return $tag_description;
}

function getSubCategoryTagKeywords($sce_id) {	
	// geeft de tag_keywords terug van een subcategorie
	
	global $website_keywords;
	
	$tag_keywords = $website_keywords;
	if ($sce_id!="") {
		$category_result = mysql_query("SELECT tag_keywords FROM sub_categories WHERE SCE_id=$sce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$tag_keywords = stripslashes(mysql_result($category_result, 0, 'tag_keywords'));
		}
	}
	return $tag_keywords;
}

function getSubCategoryUrl($sce_id) {
    // geeft de url terug waarop de subcategorie te vinden is
    
    global $use_name_urls;
    
    if (!$use_name_urls) {
    	$subcat_url = "subcategorie.php?sce_id=".$sce_id;
    } else {
    	$mce_id = getMainCategoryFromSubCategory($sce_id);
    	
    	$subcat_url = getMainCategoryName($mce_id)." ".getSubCategoryName($sce_id);
		$subcat_url = str_replace(" ","_",$subcat_url);
		$subcat_url = str_replace("/","",$subcat_url);
		$subcat_url = str_replace("'","",$subcat_url);
		$subcat_url = str_replace("(","",$subcat_url);
		$subcat_url = str_replace(")","",$subcat_url);
		$subcat_url = str_replace("&","en",$subcat_url);
		$subcat_url = str_replace("!","",$subcat_url);
		$subcat_url = urlencode(trim(strToLower($subcat_url)));
		$subcat_url .= "_s-".$sce_id.".html"; 
    }
    return $subcat_url;
}

function getSubCategoryDescription($sce_id) {
	// geeft de omschrijving terug van een subcategorie
	$category_description = "";
	if ($sce_id!="") {
		$category_result = mysql_query("SELECT description FROM sub_categories WHERE SCE_id=$sce_id") or die (mysql_error());
		if (mysql_num_rows($category_result) > 0) {
			$category_description = stripslashes(mysql_result($category_result, 0, 'description'));
		}
	}
	return $category_description;
}

function getMainCategoryFromSubCategory($sce_id) {
	// geeft de hoofdcategorie terug voor een subcategorie

	$main_category_result = mysql_query("SELECT MCE_id FROM sub_categories WHERE SCE_id=$sce_id") or die (mysql_error());
	$mce_id = "";
	if (mysql_num_rows($main_category_result) > 0) $mce_id = mysql_result($main_category_result, 0, 'MCE_id');
	return $mce_id;
}
?>
<?
$link = connecttodb($servername,$dbname,$dbuser,$dbpassword);
$uqz_id = addslashes($_SESSION['uqz_id']);
if ($uqz_id!="") {
	$qiz_id = getUserQuizQuiz($uqz_id);
	$page_title = $website_title . " - " . getQuizName($qiz_id);
} else {
	$page_title = $website_title;
}
?>
<?
$referer = $_SERVER['HTTP_REFERER'];
if ($referer!="" && strpos($referer,"quiz-it")==false) {
	$url = addslashes($referer);
	$datetime = date("Y-m-d H:i:s",mktime(date("H"),date("i"),date("s"),date("m"),date("d"),date("Y")));
	//mysql_query("INSERT INTO website_referers (url,datetime) VALUES ('$url','$datetime')") or die (mysql_error());
}
?><?
if ($_SESSION['usr_id']=="") {	
    $cookie_usr_id = addslashes($_COOKIE['usr_id']);
    $ip_address = addslashes($_SERVER['REMOTE_ADDR']);

    if ($cookie_usr_id=="") $cookie_usr_id = 0;

    // controleren of er al een user-id is voor deze cookie en ip
    $last_seen = date("Y-m-j H:i:s",mktime(date("H"),date("i"),date("s"),date("m"),date("j"),date("Y")));
    $user_result = mysql_query("SELECT USR_id FROM users WHERE USR_id=$cookie_usr_id AND ip_address='$ip_address'") or die (mysql_error());
    if (mysql_num_rows($user_result) > 0) {
        // user gevonden
        $set_usr_id = mysql_result($user_result, 0, 'USR_id');
        mysql_query("UPDATE users SET last_seen='$last_seen' WHERE USR_id=$set_usr_id") or die (mysql_error());
    } else {
        // user niet gevonden, inserten in database en cookie plaatsen
        $date_created = date("Y-m-j",mktime(date("H"),date("i"),date("s"),date("m"),date("j"),date("Y")));
        mysql_query("INSERT INTO users (ip_address,date_created,last_seen) VALUES ('$ip_address','$date_created','$last_seen')") or die (mysql_error());
        $set_usr_id = mysql_insert_id();
        setcookie("usr_id", $set_usr_id, time()+321408000);
    }
    $_SESSION['usr_id'] = $set_usr_id;
}
if ($debug) echo $_SESSION['usr_id'];


function getUserName($usr_id) {
	// geeft de naam van een gebruiker terug
	$user_name = "";
	$user_result = mysql_query("SELECT name FROM users WHERE USR_id=$usr_id") or die (mysql_error());
	if (mysql_num_rows($user_result) > 0) $user_name = stripslashes(mysql_result($user_result, 0, 'name'));
	return $user_name;
}

function clearOlderUsersNotActive() {
	// ruimt oude niet active gebruikers op die nog geen quizzes hebben gemaakt
	$mark_date = date("Y-m-d",mktime(0,0,0,date("m"),date("d")-3,date("Y")));
	mysql_query("DELETE FROM users WHERE (name is Null OR name='') AND last_seen<'$mark_date' AND USR_id NOT IN (SELECT USR_id FROM user_quizzes WHERE completed=1)") or die (mysql_error());	
	
	// opruimen oude topscores van verwijderde gebruikers
	mysql_query("DELETE FROM user_highscores WHERE USR_id NOT IN (SELECT USR_id FROM users)") or die (mysql_error());
}

// ################################### highscores #######################################

function updateUserHighScore($usr_id,$qiz_id) {
	// update de highscore op een quiz voor een gebruiker

	$highscore_result = mysql_query("SELECT calculated_time_taken, calculated_percentage_correct FROM user_quizzes WHERE USR_id=$usr_id AND QIZ_id=$qiz_id AND completed=1 ORDER BY calculated_percentage_correct DESC, calculated_time_taken LIMIT 1") or die (mysql_error());
	if (mysql_num_rows($highscore_result) > 0) {
		$time_taken = stripslashes(mysql_result($highscore_result, 0, 'calculated_time_taken'));
		$percentage = stripslashes(mysql_result($highscore_result, 0, 'calculated_percentage_correct'));
		
		mysql_query("DELETE FROM user_highscores WHERE USR_id=$usr_id AND QIZ_id=$qiz_id") or die (mysql_error());
		mysql_query("INSERT INTO user_highscores (USR_id,QIZ_id,percentage,time_taken) VALUES ($usr_id,$qiz_id,$percentage,$time_taken)") or die (mysql_error());
	}
	
	// updaten ranks
	$rank = 1;
	$score_result = mysql_query("SELECT hs.UHS_id FROM user_highscores hs INNER JOIN users u ON hs.USR_id=u.USR_id WHERE hs.QIZ_id=$qiz_id AND u.name<>'' ORDER BY hs.percentage DESC, hs.time_taken, hs.UHS_id DESC") or die (mysql_error());
	while ($row = mysql_fetch_array($score_result)) {
		$uhs_id = $row[UHS_id];
		mysql_query("UPDATE user_highscores SET rank=$rank WHERE UHS_id=$uhs_id") or die (mysql_error());
		$rank++;
	}
}

function getUserHighScoresList($usr_id) {
	// geeft een lijst terug met topscores van een gebruiker
	
	$scores_result = mysql_query("SELECT * FROM user_highscores WHERE USR_id=$usr_id ORDER BY rank") or die (mysql_error());
	$scores_counter = 0;
	while ($row = mysql_fetch_array($scores_result)) {
		$scores_list[$scores_counter][QIZ_id] = $row[QIZ_id];
		$scores_list[$scores_counter][percentage] = $row[percentage];
		$scores_list[$scores_counter][time_taken] = $row[time_taken];
		$scores_list[$scores_counter][rank] = $row[rank];
		$scores_counter++;
	}
	return $scores_list;
}

function getUserQuizWithNoScoreList($usr_id) {
	// geeft een lijst terug met quizzes waarvoor een gebruiker nog geen topscore heeft
	
	$quiz_result = mysql_query("SELECT QIZ_id FROM quizzes WHERE active=1 AND deleted=0 AND QIZ_id NOT IN (SELECT QIZ_id FROM user_highscores WHERE USR_id=$usr_id)") or die (mysql_error());
	$quiz_counter = 0;
	while ($row = mysql_fetch_array($quiz_result)) {
		$quizzes_list[$quiz_counter] = $row[QIZ_id];
		$quiz_counter++;
	}
	return $quizzes_list;
}
?>
<html>
<head>
	<title><? echo $page_title; ?></title>
	<META name="keywords" content="<? echo $website_keywords; ?>">
	<META name="description" content="<? echo $website_description; ?>"> 	
	<link href="styles.css" rel="stylesheet" type="text/css">
</head>


<body>
	<table border="0" cellpadding="0" cellspacing="0" width="100%" height="100%">
		<tr>
			<td align="center" valign="top">
				<table border="0" cellpadding="0" cellspacing="0" width="1000">
					<tr><td><table border="0" cellpadding="0" cellspacing="0" width="1000" height="134">
	<tr>
		<td width="413"><a href="index.php"><img src="images/quiz-it_logo.gif" width="413" height="134" border="0"></a></td>
		<td width="401">&nbsp;</td>
		<td width="186"><img src="images/brains.gif" width="186" height="134"></td>		
	</tr>
</table>
</td></tr>
					<tr>
						<td>
							<table border="0" cellpadding="0" cellspacing="0" width="1000">
								<tr>
									<td width="250" valign="top">
										<table border="0" cellpadding="0" cellspacing="0" width="250">
											<tr><td><script language="javascript">
	function navigatieMuisOver(element,element_name) {
		element.style.backgroundColor='#F19E00';
		eval(element_name+'_link').style.color = '#000000';
	}
	function navigatieMuisAf(element,element_name) {
		element.style.backgroundColor='';
		eval(element_name+'_link').style.color = '#BE7E02';		
	}
	function navigatieMuisKlik(hlink) {
		document.location.href = hlink;
	}
	function addBookMark() {
		window.external.AddFavorite('http://www.quiz-it.nl', 'Quiz-it.nl - Test je kennis met leuke vragen!');
	}
</script>
<table cellpadding="0" cellspacing="0" width="250" class="yellow_bg">
	<tr>
		<td>
			<table cellpadding="0" cellspacing="0" width="246">
				<tr><td><img src="images/title_hoofdmenu.gif" width="145" height="40"></td></tr>
				<tr><td><? displayNavigationOption("Home","index.php","home"); ?></td></tr>
				<tr><td><? displayNavigationOption("Categorie�n","categorieen.php","categorieen"); ?></td></tr>
				<tr><td><? displayNavigationOption("Hoe werkt het?","hoe_werkt_het.php","hoewerkthet"); ?></td></tr>
				<tr><td><? displayNavigationOption("Jouw topscores","jouw_topscores.php?usr_id=".$_SESSION['usr_id'],"jouwtopscores"); ?></td></tr>
				<tr><td><? displayNavigationOption("Gastenboek","gastenboek.php","gastenboek"); ?></td></tr>
				<tr><td><? displayNavigationOption("Maak favoriet","javascript:addBookMark();","maakfavoriet"); ?></td></tr>
				<tr><td><? displayNavigationOption("Contact","contact.php","contact"); ?></td></tr>
				<tr><td height="15"><img src="images/transpix.gif" width="1" height="1"></td></tr>
			</table>
		</td>
	</tr>
</table>
<?
function displayNavigationOption($name,$hlink,$element_name) {
	// toont een menu-item in de navigatie
	?>
	<table cellpadding="0" cellspacing="0" width="246" id="<? echo $element_name; ?>" class="navigation_option" onMouseOver="javascript:navigatieMuisOver(this,'<? echo $element_name; ?>');" onMouseOut="javascript:navigatieMuisAf(this,'<? echo $element_name; ?>');" onClick="javascript:navigatieMuisKlik('<? echo $hlink; ?>');">
		<tr>
			<td><a href="<? echo $hlink; ?>" class="navigation_link" id="<? echo $element_name; ?>_link"><? echo $name; ?></a></td>
		</tr>
	</table>
	<?
}
?></td></tr>
											<tr><td height="12"><img src="images/transpix.gif" width="1" height="1"></td></tr>
										</table>
									</td>
									<td width="12"><img src="images/transpix.gif" width="1" height="1"></td>
									<td width="606" valign="top">
										<table border="0" cellpadding="0" cellspacing="0" width="606">
											<tr><td><?
switch ($_GET['command']) {

	case "start_quiz": makeUserQuiz(); displayUserQuizQuestion(); break;
	case "pick_option":
			if ($_SESSION['uqz_id']=="") {
				$qtn_id= addslashes($_GET['qtn_id']);
				if ($qtn_id!="") {
					$qiz_id = getQuestionQuiz($qtn_id);
					?>
					<script language="javascript">
						document.location.href = 'quiz.php?qiz_id=<? echo $qiz_id; ?>';
					</script>
					<?
				}
			} else {
				answerUserQuizQuestion();
				if (getNextUserQuizQuestion($_SESSION['uqz_id'])!="") {
					displayUserQuizQuestion();
				} else {
					finishUserQuiz();
					displayUserQuizFinish();
				}
			}
			break;
	case "enter_user_name" : enterUserName(); break;
	case "topscores" : displayQuizTopScores(); break;

    default: displayQuizStart(); break;
}
?>
</td></tr>
											<tr><td height="6"><img src="images/transpix.gif" width="1" height="1"></td></tr>
											<tr><td align="left"><script type="text/javascript"><!--
google_ad_client = "pub-3519187082459864";
//468x60, gemaakt 4-12-07
google_ad_slot = "9532348766";
google_ad_width = 468;
google_ad_height = 60;
//--></script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script></td></tr>
										</table>
									</td>
									<? if ($_SESSION['uqz_id']!="") { ?>
										<td width="132" valign="top" align="right"><script type="text/javascript"><!--
google_ad_client = "pub-3519187082459864";
//120x600, gemaakt 4-12-07
google_ad_slot = "1343902398";
google_ad_width = 120;
google_ad_height = 600;
//--></script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script></td>
									<? } ?>
								</tr>
							</table>
						</td>
					</tr>
					<tr><td height="10"><img src="images/transpix.gif" width="1" height="1"></td></tr>
				</table>
			</td>
		</tr>
	</table>
</body>
</html>
<?
disconnectdb($link);
?>
<script language="javascript">
	<?
	if (rand(1,20)==11) {
		?>
		var ran_number= (Math.random()*30)*100+500;
		setTimeout("jumpInPage()",ran_number);
		<?
	} else {
		?>
		jumpInPage();
		<?
	}
	?>
	function jumpInPage() {
		document.location.href = '#question';
	}
</script>