function newImage(arg) {
	rslt = new Image();
	rslt.src = arg;
	return rslt;
}


function preloadImages() {
	if (document.images) {
		about_on = newImage("images/nav/about_on.png");
		technology_on = newImage("images/nav/technology_on.png");
		products_on = newImage("images/nav/products_on.png");
		partners_on = newImage("images/nav/partners_on.png");
		investors_on = newImage("images/nav/investors_on.png");
		news_on = newImage("images/nav/news_on.png");
		careers_on = newImage("images/nav/careers_on.png");
		links_on = newImage("images/nav/resources_on.png");
		contact_on = newImage("images/nav/contact_on.png");
		
		//subnav items
		about0_on = newImage("images/subnav/about0_on.png");
		about1_on = newImage("images/subnav/about1_on.png");
		careers0_on = newImage("images/subnav/careers0_on.png");
		careers1_on = newImage("images/subnav/careers1_on.png");
		careers2_on = newImage("images/subnav/careers2_on.png");
		news0_on = newImage("images/subnav/about0_on.png");
		news1_on = newImage("images/subnav/about1_on.png");
		partners0_on = newImage("images/subnav/partners0_on.png");
		products0_on = newImage("images/subnav/products0_on.png");
		products1_on = newImage("images/subnav/products1_on.png");
		products2_on = newImage("images/subnav/products2_on.png");
		technology0_on = newImage("images/subnav/technology0_on.png");
		technology1_on = newImage("images/subnav/technology1_on.png");
		technology2_on = newImage("images/subnav/technology2_on.png");
		technology3_on = newImage("images/subnav/technology3_on.png");
	}
}


function setupNav() {
    setupNavListItem('about');
    setupNavListItem('technology');
    setupNavListItem('products');
    setupNavListItem('partners');
    setupNavListItem('investors');
    setupNavListItem('news');
    setupNavListItem('careers');
    setupNavListItem('resources');
	setupNavListItem('contact');
	
	setupSubNavListItem('about0');
	setupSubNavListItem('about1');
    setupSubNavListItem('technology0');
	setupSubNavListItem('technology1');
	setupSubNavListItem('technology2');
	setupSubNavListItem('technology3');
    setupSubNavListItem('products0');
	setupSubNavListItem('products1');
    setupSubNavListItem('partners0');
    setupSubNavListItem('news0');
	setupSubNavListItem('news1');
	setupSubNavListItem('careers0');
	setupSubNavListItem('careers1');
	setupSubNavListItem('careers2');
}

function setupNavListItem(item) {
	o = document.getElementById("a_"+item);
	if(o != null)
	{
		o.onmouseover=function() {
        	document.getElementById(item).src = 'images/nav/'+item+'_on.png';
        	return true;
	    
		}
		o.onmouseout=function() {
        	document.getElementById(item).src = 'images/nav/'+item+'.png';
       		return true;
		}
	}
}

function setupSubNavListItem(item) {
	o = document.getElementById("a_"+item);
	if(o != null)
	{
		o.onmouseover=function() {
        	document.getElementById(item).src = 'images/subnav/'+item+'_on.png';
        	return true;
	    
		}
		o.onmouseout=function() {
        	document.getElementById(item).src = 'images/subnav/'+item+'.png';
       		return true;
		}
	}
}