function start() {
	
	var code = $("#code").val();
	var rnd = Math.round(Math.random()*100000000000000);
	
	if(code.length>=4) {
		$("#start INPUT[type=button]").attr("disabled", "disabled");
		$("#proef INPUT[type=button]").attr("disabled", "disabled");
	
		$.getJSON("../json/examen.php", {"code": code, "rnd": rnd, "license": $("META[name=license]").attr("content")}, function(contents) {
			data = contents;
			
			if(data!=null && data.questions!=null && data.questions.length>0) {
				initEvents();
				
				if(msie) {
					$("#tabs").data("disabled.tabs", []);
					$("#tabs").tabs("select",2);
					$("#tabs").data("disabled.tabs", [0,1,3,4,5]);
				} else {
					$("#tabs").data("disabled.tabs", []);
					$("#tabs").tabs("select",2);
					$("#tabs").data("disabled.tabs", [3,4,5]);
				}
				$("#terminal IMG").each(function() {
					$(this).attr("src", $(this).attr("src"));
				});
				
				// Google
				$.getScript("../script/google.js", function(){});
				
				// Wachtscherm
				$("#questionImage").css({
					"background": "transparent url('../images/examenloader.gif') -40px -48px no-repeat"
				});
				
				timer = window.setTimeout("preload()", 1000);
			} else {
				$("#ongeldig").dialog("open");
			}
			
			$("#code").val("");
			$("#start INPUT[type=button]").removeAttr("disabled");
			$("#proef INPUT[type=button]").removeAttr("disabled");
			
		});
	} else {
		$("#ongeldig").dialog("open");
	}
}

function proef() {
	
	$("#start INPUT[type=button]").attr("disabled", "disabled");
	$("#proef INPUT[type=button]").attr("disabled", "disabled");
	
	var code = "proef";
	var rnd = Math.round(Math.random()*100000000000000);

	$.getJSON("../json/examen.php", {"code": code, "rnd": rnd, "license": $("META[name=license]").attr("content")}, function(contents) {
		data = contents;
		
		if(data!=null && data.questions!=null && data.questions.length>0) {
			initEvents();
			
			if(msie) {
				$("#tabs").data("disabled.tabs", []);
				$("#tabs").tabs("select",2);
				$("#tabs").data("disabled.tabs", [0,1,3,4,5]);
			} else {
				$("#tabs").data("disabled.tabs", []);
				$("#tabs").tabs("select",2);
				$("#tabs").data("disabled.tabs", [3,4,5]);
			}
			$("#terminal IMG").each(function() {
				$(this).attr("src", $(this).attr("src"));
			});
			
			// Wachtscherm
			$("#questionImage").css({
				"background": "transparent url('../images/examenloader.gif') -40px -48px no-repeat"
			});
			
			timer = window.setTimeout("preload()", 1000);
		}
		
		$("#code").val("");
		$("#start INPUT[type=button]").removeAttr("disabled");
		$("#proef INPUT[type=button]").removeAttr("disabled");
	});

}

function preload() {
	loadQuestions();
	loadImages();
	loadExplanations();
	
	next();
}

function loadImages() {
	for(var i=0; i<data.questions.length; i++) {
		$.preloadImages(data.questions[i].imgUrl);
	}
}

jQuery.preloadImages = function() {
	$("#preload").css("display", "none");
	$("#preload").html("");
	for(var i=0; i<arguments.length; i++) {
		//jQuery("<img>").attr("src", arguments[i]);
		$("#preload").append("<IMG src=\"" + arguments[i] + "\">");
	}
}

function loadQuestions() {
	if(soundEnabled) {
		for(var i=0; i<data.questions.length; i++) {
			if(soundManager.canPlayURL(data.questions[i].sndUrl)) {
				data.questions[i].sndObj = soundManager.createSound({
					id: data.questions[i].sndUrl,
					url: data.questions[i].sndUrl,
					autoLoad: true,
					autoPlay: false,
					onfinish: function() {
						soundManager.stopAll();
						progressbar();
					}
				});
			}
		}
	}
}

function loadExplanations() {
	if(soundEnabled) {
		for(var i=0; i<data.questions.length; i++) {
			if(soundManager.canPlayURL(data.questions[i].explUrl)) {
				data.questions[i].explObj = soundManager.createSound({
					id: data.questions[i].explUrl,
					url: data.questions[i].explUrl,
					autoLoad: true,
					autoPlay: false,
					onfinish: function() {
						soundManager.stopAll();
					}
				});
			}
		}
	}
}