var image="";
var banners=0;
function cycle() {
  if (++banners > 4) banners=1;
    loadbanners();
    document.banner1.src = image;
    window.setTimeout('cycle();',4000);
  }
function loadbanners() {
   if (banners==1)
      {
      image="images/promo01.jpg";
      }
   if (banners==2)
      {
      image="images/promo02.jpg";
      }
   if (banners==3)
      {
      image="images/promo03.jpg";
      }
   if (banners==4)
      {
      image="images/promo04.jpg";
      }
}