var image_count = 0,
    dhtmlok = false,
    images_needed = 0;

function initialize(count) {

    images_needed = count;

} // end function initialize

function count_images() {

   if (++image_count == images_needed) {

      dhtmlok = true;

   }

} // end function count_images


function changeImage(name, newsrc) {

   if (dhtmlok) {

      document.images[name].src = newsrc;

   }


} // end function changeImage


function preloadImages() {

  var doc = document;

  if (doc.images) { 

     var myImages = new Array();

     var args = preloadImages.arguments;

     initialize(args.length);

     for(i = 0; i < args.length; i++) {

        myImages[i] = new Image();
        myImages[i].onload = count_images;
        myImages[i].src = args[i];

     }

  }

}