function loadStartup() {
	preLoadNavButtons();
	loadNavButtons("logo");
	loadNavButtons("btn_about");
	loadNavButtons("btn_portfolio");
	loadNavButtons("btn_services");
	loadNavButtons("btn_contact");
	loadNavButtons("btn_links");
}

function loadNavButtons(navId) {
	if (document.getElementById) { 
		var ImgId = document.getElementById(navId);
		var btnSrc = "images/" + navId + ".jpg";
		var btnOver = "images/" + navId + "_over.jpg";
		ImgId.src =  btnSrc;
		holder = ImgId.parentNode;
		holder.onmouseover = function(){swapImage(navId, btnOver)};
		holder.onmouseout = function(){swapImage(navId, btnSrc)};
	};
}

function preLoadNavButtons() {
		var img1 = new Image(); img1.src = "images/logo_over.jpg";
		var img2 = new Image(); img2.src = "images/btn_about_over.jpg";
		var img3 = new Image(); img3.src = "images/btn_portfolio_over.jpg";
		var img4 = new Image(); img4.src = "images/btn_services_over.jpg";
		var img5 = new Image(); img5.src = "images/btn_contact_over.jpg";
		var img6 = new Image(); img6.src = "images/btn_links_over.jpg";
}