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

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		about_us_btn_over = newImage(image_directory + "images/gui/left/about_us_btn_over.jpg");
		asep_tech_systems_btn_over = newImage(image_directory + "images/gui/left/asep-tech_systems_btn_over.jpg");
		whats_new_btn_over = newImage(image_directory + "images/gui/left/whats_new_btn_over.jpg");
		technical_papers_btn_over = newImage(image_directory + "images/gui/left/technical_papers_btn_over.jpg");
		related_links_btn_over = newImage(image_directory + "images/gui/left/related_links_btn_over.jpg");
		contact_us_btn_over = newImage(image_directory + "images/gui/left/contact_us_btn_over.jpg");
		customer_support_btn_over = newImage(image_directory + "images/gui/left/customer_support_btn_over.jpg");
		rep_login_btn_over = newImage(image_directory + "images/gui/left/rep_login_btn_over.jpg");
		site_map_btn_over = newImage(image_directory + "images/gui/left/site_map_btn_over.jpg");
		home_btn_over = newImage(image_directory + "images/gui/left/home_btn_over.jpg");
		preloadFlag = true;
	}
}