window.onload = function(){
	if ( document.getElementById ) {
		imgPrefix = "/images/";
		navItems = ["nav-about", "nav-careers", "nav-contact"];
		navTargets = [];
		navTargets["nav-about"] = "nav-services";
		navTargets["nav-careers"] = "nav-about";
		navTargets["nav-contact"] = "nav-careers";
		img = new Image;
		img.src = imgPrefix + "nav_services_2.jpg";
		
		for( i=0; i<navItems.length; i++ ) {
			element = document.getElementById(navItems[i]);
			img = new Image;
			img.src = imgPrefix + navItems[i].replace("-", "_") + "_2.jpg";
			img2 = new Image;
			img2.src = imgPrefix + navTargets[navItems[i]].replace("-", "_") + "_3.jpg";
			element.onmouseover = function(){
				targetId = navTargets[this.id];
				document.getElementById(targetId).style.backgroundImage = "url(" + imgPrefix + targetId.replace("-", "_") + "_3.jpg)";
			};
			element.onmouseout = function(){
				targetId = navTargets[this.id];
				document.getElementById(targetId).style.backgroundImage = "";
			};
		}
	}
};