function cssPreloadImages() {
	var ims = new Array ("images/menu_01_on.jpg","images/menu_02_on.jpg","images/menu_03_on.jpg","images/menu_04_on.jpg","images/menu_05_on.jpg");
	var i;
	for (i=0; i<ims.length; i++)
		{ 
		var img = new Image();
		img.src = ims[i];
		}
}
if (window.attachEvent) {
	// IE
	window.attachEvent("onload", cssPreloadImages);
	
} else {
	// DOM
	window.addEventListener("load", cssPreloadImages, false);
	
}