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) {
		catalog_over = newImage("images/menu-images/catalog-over.gif");
		sensors_over = newImage("images/menu-images/sensors-over.gif");
		vm600_over = newImage("images/menu-images/vm600-over.gif");
		monitors_over = newImage("images/menu-images/monitors-over.gif");
		detector_over = newImage("images/menu-images/detector-over.gif");
		scanner_over = newImage("images/menu-images/scanner-over.gif");
		optical_over = newImage("images/menu-images/optical-over.gif");
		ignition_over = newImage("images/menu-images/ignition-over.gif");
		support_over = newImage("images/menu-images/support-over.gif");
		links_over = newImage("images/menu-images/links-over.gif");
		contact_over = newImage("images/menu-images/contact-over.gif");
		site_over = newImage("images/menu-images/site-over.gif");
		home_over = newImage("images/menu-images/home-over.gif");
		preloadFlag = true;
	}
}