if (document.images) {
   img1 = new Image(); img1.src = "mo2.gif";
   img2 = new Image(); img2.src = "to2.gif";
   img3 = new Image(); img3.src = "su2.gif";
}
function setImage(img, image) {
   if (img) {
      img.src = image;
   }
}