var img = new Array();
var imgNo = 1;    
var imgEnd = 5; 

// pre-load
function preloadImgs() {
if(document.images)
{
   for(i = 1; i <= imgEnd; i++)
   {
     img[i] = new Image();
     img[i].src = "images/menu-hover_0" + i + ".jpg";
   }
}}