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

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

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		var button_login = loginNewImage("loginimages/button_login_over.gif");
		var button_register = loginNewImage("loginimages/button_register_over.gif");
		var button_demo = loginNewImage("loginimages/button_demo_over.gif");
		var button_purchase = loginNewImage("loginimages/button_purchase_over.gif");
		var button_accesscode = loginNewImage("loginimages/button_request_access_over.gif");
		preloadFlag = true;
	}
}