if(document.images){
   var imgOut = new Object();
	 imgOut["lon"] = new Image(152, 128);
   imgOut["lon"].src = "images/th-long-island-landscapes.jpg";
   imgOut["but"] = new Image(153, 127);
   imgOut["but"].src = "images/th-butterflies.jpg";
   imgOut["gal"] = new Image(150, 127);
   imgOut["gal"].src = "images/th-galapagos-islands.jpg";
   imgOut["col"] = new Image(153, 127);
   imgOut["col"].src = "images/th-colorado-impressions.jpg";
   imgOut["ant"] = new Image(152, 123);
   imgOut["ant"].src = "images/th-antarctica.jpg";
	 imgOut["pen"] = new Image(153, 125);
   imgOut["pen"].src = "images/th-penguins.jpg";
	 imgOut["chn"] = new Image(152, 123);
   imgOut["chn"].src = "images/th-china.jpg";
	 imgOut["ire"] = new Image(153, 123);
   imgOut["ire"].src = "images/th-ireland.jpg";
	 imgOut["sed"] = new Image(151, 124);
   imgOut["sed"].src = "images/th-sedona.jpg";
	 imgOut["nov"] = new Image(153, 124);
   imgOut["nov"].src = "images/th-nova-scotia.jpg";
	 imgOut["eas"] = new Image(150, 124);
   imgOut["eas"].src = "images/th-easter-island.jpg";
	 imgOut["flo"] = new Image(153, 124);
   imgOut["flo"].src = "images/th-flowers.jpg";
	 imgOut["wam"] = new Image(153, 124);
   imgOut["wam"].src = "images/th-water-music.jpg";
	 imgOut["mon"] = new Image(153, 124);
   imgOut["mon"].src = "images/th-monet.jpg";

   var imgOver = new Object();
   imgOver["lon"] = new Image(152, 128);
   imgOver["lon"].src = "images/th-long-island-landscapes-over.jpg";
   imgOver["but"] = new Image(153, 127);
   imgOver["but"].src = "images/th-butterflies-over.jpg";
   imgOver["gal"] = new Image(150, 127);
   imgOver["gal"].src = "images/th-galapagos-islands-over.jpg";
   imgOver["col"] = new Image(153, 127);
   imgOver["col"].src = "images/th-colorado-impressions-over.jpg";
   imgOver["ant"] = new Image(152, 123);
   imgOver["ant"].src = "images/th-antarctica-over.jpg";
	 imgOver["pen"] = new Image(153, 125);
   imgOver["pen"].src = "images/th-penguins-over.jpg";
	 imgOver["chn"] = new Image(152, 123);
   imgOver["chn"].src = "images/th-china-over.jpg";
	 imgOver["ire"] = new Image(153, 123);
   imgOver["ire"].src = "images/th-ireland-over.jpg";
	 imgOver["sed"] = new Image(151, 124);
   imgOver["sed"].src = "images/th-sedona-over.jpg";
	 imgOver["nov"] = new Image(153, 124);
   imgOver["nov"].src = "images/th-nova-scotia-over.jpg";
	 imgOver["eas"] = new Image(150, 124);
   imgOver["eas"].src = "images/th-easter-island-over.jpg";
	 imgOver["flo"] = new Image(153, 124);
   imgOver["flo"].src = "images/th-flowers-over.jpg";
	 imgOver["wam"] = new Image(153, 124);
   imgOver["wam"].src = "images/th-water-music-over.jpg";
	 imgOver["mon"] = new Image(153, 124);
   imgOver["mon"].src = "images/th-monet-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"){
            switch (evt.type){
               case "mouseover":
                  elem.src = imgOver[elem.id].src;
                  break;
               case "mouseout":
                  elem.src = imgOut[elem.id].src;
                  break;
            }
         }
      }
   }
}
document.onmouseover = swapImage;
document.onmouseout = swapImage;