if (document.images) 
{
   img1 = new Image();
   img2 = new Image();
   img3 = new Image();
   img4 = new Image();
   img5 = new Image();
   img6 = new Image();
   img7 = new Image();
   img1.src = "img/ufheader.png";   
   img2.src = "img/shoe.gif";   
   img3.src = "img/shoe_a.gif";
   img4.src = "img/shoe_b.gif";
   img5.src = "img/shoe_c.gif";
   img6.src = "img/shoe_d.gif";
   img7.src = "img/shoe_e.gif";
}