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) {
/*		btn_home = newImage("images/btn_home_over.gif");
		btn_about = newImage("images/btn_about.gif");
		btn_products = newImage("images/btn_products.gif");
		btn_support = newImage("images/btn_support.gif");
		btn_contact = newImage("images/btn_contact.gif");
*/		preloadFlag = true;
	}
}