function preload_img()
{ 
  var img_list = preload_img.arguments;
  if (document.preloadlist == null) 
    document.preloadlist = new Array();
  var top = document.preloadlist.length;
  for (var i=0; i < img_list.length-1; i++) {
    document.preloadlist[top+i] = new Image;
    document.preloadlist[top+i].src = img_list[i+1];
  } 
}