function preloadMainImages() {
if (document.images)
	{
	var btn_home_roll = new Image
		btn_home_roll.src = "graphics/btn_home_over.gif"
	var btn_quit_roll = new Image
		btn_quit_roll.src = "graphics/btn_quit_over.gif"
	var btn_content_roll = new Image
		btn_content_roll.src = "graphics/btn_content_over.gif"
	var btn_credits_roll = new Image
		btn_credits_roll.src = "graphics/btn_credits_over.gif"
	var btn_contact_roll = new Image
		btn_contact_roll.src = "graphics/btn_contact_over.gif"
	var btn_glossary_roll = new Image
		btn_glossary_roll.src = "graphics/btn_glossary_over.gif"
	var btn_journey_roll = new Image
		btn_journey_roll.src = "graphics/btn_journey_over.gif"
	var btn_blackhole_roll = new Image
		btn_blackhole_roll.src = "graphics/btn_blackhole_over.gif"
	var btn_replay_roll = new Image
		btn_replay_roll.src = "graphics/btn_replay_over.jpg"
	var btn_backcontents_roll = new Image
		btn_backcontents_roll.src = "graphics/btn_backcontents_over.gif"
	var btn_nexttopic_roll = new Image
		btn_nexttopic_roll.src = "graphics/btn_nexttopic_over.gif"
	var btn_previoustopic_roll = new Image
		btn_previoustopic_roll.src = "graphics/btn_previoustopic_over.gif"
	var btn_submit_roll = new Image
		btn_submit_roll.src = "graphics/btn_submit_over.gif"
	var btn_reset_roll = new Image
		btn_reset_roll.src = "graphics/btn_reset_over.gif"
	}
}

function changeImages(sName,sImage)
	{
	if (document.images)
		{
		document.images[sName].src = sImage
		}
	}

function openWindow(theURL,winName,features)
	{
	window.open(theURL,winName,features).focus();
	}

function closeWindow()
	{
	window.close();
	}

if (document.layers)
	{
	origWidth = innerWidth;
	origHeight = innerHeight;
	}
function reloadPage()
	{
	if (innerWidth != origWidth || innerHeight != origHeight)
	location.reload();
	}
if (document.layers)
	onresize=reloadPage;
	
function goHistory()
	{
	window.history.go(-1);
	}
	
function upgradeFlash()
	{
	currMessage='<p id="print_upgrade"><br />This page contains a Flash movie. It requires the Flash '+versionNum+'+ plug-in. <a href="http://www.macromedia.com/shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash" class="whitelink">Get Flash</a> (for free!)</p>';
	}

var replaceChars=new Array();
replaceChars[0]=/''/g;
replaceChars[1]="|";

function updateVariable(var_id)
	{
	this[var_id]=this[var_id].replace(replaceChars[0], "&quot;");
	this[var_id]=this[var_id].replace(replaceChars[1], "&");
	return this[var_id];
	}
	
bName = navigator.appName;
bVer = parseInt(navigator.appVersion);
if (navigator.userAgent.indexOf('Safari')>-1){ver = "isSafari"}
else if (bName == "Netscape" && bVer >= 5) {ver="isNewNetscape";}
else if (bName == "Microsoft Internet Explorer") {ver="isIE";}
else if (bName == "Mozilla" && bVer >= -1) {ver="isMozilla";}
else {ver="nonGecko";}

if (document.layers) {
	origWidth = window.innerWidth;
	origHeight = window.innerHeight;
	}
	
function printIt()
	{  
	if (window.print)
		{
		window.print();  
		}
	else
		{
		var WebBrowser = '<object id="WebBrowser1" width="0" height="0" classid="CLSID:8856F961-340A-11D0-A96B-00C04FD705A2"></object>';
		document.body.insertAdjacentHTML('beforeEnd', WebBrowser);
		WebBrowser1.ExecWB(6, 2);
		}
	}
	
function parentURL(url)
	{
	window.opener.location.href=url;
	window.focus();
	}