// pre-cache images used for menu rollovers
if (document.images) {
	var homeOn = new Image();
	homeOn.src = "buttons/home_on.gif";
	var homeOff = new Image();
	homeOff.src = "buttons/home_off.gif";

	var aboutOn = new Image();
	aboutOn.src = "buttons/about_on.gif";
	var aboutOff = new Image();
	aboutOff.src = "buttons/about_off.gif";
		
	var servicesOn = new Image();
	servicesOn.src = "buttons/all_services_on.gif";
	var servicesOff = new Image();
	servicesOff.src = "buttons/all_services_off.gif";

	var productsOn = new Image();
	productsOn.src = "buttons/products_on.gif";
	var productsOff = new Image();
	productsOff.src = "buttons/products_off.gif";

	var newsOn = new Image();
	newsOn.src = "buttons/news_on.gif";
	var newsOff = new Image();
	newsOff.src = "buttons/news_off.gif";

	var careersOn = new Image();
	careersOn.src = "buttons/careers_on.gif";
	var careersOff = new Image();
	careersOff.src = "buttons/careers_off.gif";
	
	var contactOn = new Image();
	contactOn.src = "buttons/contact_on.gif";
	var contactOff = new Image();
	contactOff.src = "buttons/contact_off.gif";

	var sitemapOn = new Image();
	sitemapOn.src = "buttons/sitemap_on.gif";
	var sitemapOff = new Image();
	sitemapOff.src = "buttons/sitemap_off.gif";
}

// main mouseover event handlers for menu links - does rollover and activates submenu (if applicable)
function doMenuOver(name, hasSubmenu) {
	// turn menu image on
	if (document.images) document["img_" + name].src = eval(name + "On.src");

	// if this menu has a submenu, turn that layer on
	if (hasSubmenu)	doSubmenuOver(name);
}

function doMenuOut(name, hasSubmenu) {
	// turn menu image off - all browsers
	if (document.images) document["img_" + name].src = eval(name + "Off.src");

	// if this menu has a submenu, turn that layer off
	if (hasSubmenu)	doSubmenuOut(name);
}

function doSubmenuOver(name) {
	if (document.all) {
		// IE 4+
		var anchor = document.all["a_" + name];
		var layer = document.all["div_" + name].style;
		layer.left = getPageOffsetLeft(anchor);
		layer.top = getPageOffsetTop(anchor) + 18;
		layer.visibility = "visible";
	}
}

function doSubmenuOut(name) {
	if (document.all) {
		// IE 4+
		document.all["div_" + name].style.visibility = "hidden";
	}
}

// functions for IE to get position of an object
function getPageOffsetLeft(el) {
	var ol = el.offsetLeft;
	while ((el = el.offsetParent) != null) ol += el.offsetLeft;
	return ol;
}

function getPageOffsetTop (el) {
	var ot = el.offsetTop;
	while ((el = el.offsetParent) != null) ot += el.offsetTop;
	return ot;
}