if(document.images){
 var imgOut = new Image(63, 19);
 imgOut.src = "images/handle.jpg";
 
 var imgOver = new Image(63, 19);
 imgOver.src = "images/handle-over.jpg";
}

function swapImage(evt){
   if(document.images){
      evt = (evt) ? evt : ((window.event) ? window.event : null);
      if(evt){
         var elem = (evt.target) ? evt.target : ((evt.srcElement) ? evt.srcElement : null);
         if(elem && ((elem.className == "swappable")||(elem.className == "swappable sfhover"))){
						var imgID = "img-" + elem.parentNode.id;
						switch (evt.type){
               case "mouseover":
							 		elem.className+=" sfhover";
                  document.images[imgID].src = imgOver.src;
                  break;
               case "mouseout":
							    elem.className = elem.className.replace(new RegExp(" sfhover\\b"), "");
                  document.images[imgID].src = imgOut.src;
                  break;
            }
         }
      }
   }
}
document.onmouseover = swapImage;
document.onmouseout = swapImage;