if (document.images)
{
  preload_image_object = new Image();
  // set image url
  image_url = new Array();
  image_url[0] = "graphics/newdesign/menu1_on.gif";
  image_url[1] = "graphics/newdesign/menu2_on.gif";
  image_url[2] = "graphics/newdesign/menu3_on.gif";
  image_url[3] = "graphics/newdesign/menu4_on.gif";
  image_url[4] = "graphics/newdesign/menu5_on.gif";

   var i = 0;
   for(i=0; i<=4; i++) 
	 preload_image_object.src = image_url[i];
}