var navMainTopics = new Array();
var currentMainTopic = "home" ;

function topnavover(topic)
{
	return(topnav(topic, true));
}

function topnavout(topic)
{
	return(topnav(topic, false));
}

function topnav (topic, isOver) {
	
	var na;

	if (!browserJS_OK)
	{
		return(true);
	}

	na = navMainTopics[topic];

	// 
	// Setup image swap array.
	//

	window.status = na.helptext;

	if (isOver)
	{
		loadNavImage(na.navOver);
		document.images[topic].src = na.navOver.src;
	} else {
		loadNavImage(na.navNormal);
		document.images[topic].src = na.navNormal.src;
	}

	return true;
}

function topnavclick(topic)
{
	if (!browserJS_OK)
	{
		return false;
	}
	if (topic == currentMainTopic)
	{
		return true;
	}

	currentMainTopic = topic;
	na = navMainTopics[topic];
	loadNavImage(na.bannerAnim);
	parent.banner.document.images["currentTopic"].src = na.bannerAnim.src;

	return false;
}


function create_navtopic(topic, helptext)
{
	var		na = new Object();

	na.name = topic;
	na.page = "topic" + "/" + topic + "_frame.html";
	na.helptext = helptext;

	na.navImgBase = "navtop_" + topic;

	na.navNormal = createNavImage("images/" + na.navImgBase + ".gif");
	loadNavImage(na.navNormal);

	na.navOver = createNavImage("images/" + na.navImgBase + "_hilite.gif");
	loadNavImage(na.navOver);


	na.bannerImgBase = "banner_" + topic;

	na.bannerStatic = createNavImage("images/" + na.bannerImgBase + ".gif");
//	loadNavImage(na.bannerStatic);

	na.bannerAnim = createNavImage("images/" + na.bannerImgBase + "_anim.gif");
//	loadNavImage(na.bannerAnim);

	navMainTopics[topic] = na;
}