if(document.images) {
  var i = 0;
  while (document.images[i]) {
    var isrc = document.images[i].src;
    var pz = isrc.lastIndexOf("/") + 1;
    var offName = isrc.substring(pz, isrc.length);
    if (offName.indexOf("off__") == 0) {
      var imgdir = isrc.substring(0, pz);
      var onName = "on__" + offName.substring(5, offName.length);
      var iname = document.images[i].name;
          var mid = "";
          var iwidth = document.images[i].width;
          var iheight = document.images[i].height;
          if (iwidth != "" && iheight != "") {
            mid = iwidth + "," + iheight;
          }
      eval("z" + iname + " = new Image (" + mid + ");");
      eval("z" + iname + ".src = '" + imgdir + onName + "';");
      eval("y" + iname + " = new Image (" + mid + ");");
      eval("y" + iname + ".src = '" + imgdir + offName + "';");
    }
    i++;
  }
  go_no = true;
}