function rollover() {
          if (!document.getElementById) return
          var imgOrSrc;
          var imgPreload = new Array();
          var images = document.getElementsByTagName('img');
          for (var i = 0; i < images.length; i++) {
          if (images[i].getAttribute('rsrc')) {
            imgPreload[i] = new Image();
            imgPreload[i].src = images[i].getAttribute('rsrc');
            images[i].onmouseover = function() {
              imgOrSrc = this.getAttribute('src');
              this.setAttribute('src',this.getAttribute('rsrc'))
              }
          images[i].onmouseout = function() {
            this.setAttribute('src',imgOrSrc)
          }
          }
        }
      }