if (document.images) {

          img1on = new Image(130,62);
          img1on.src = "gif/homeon.gif";

          img2on = new Image(130,62);
          img2on.src = "gif/calon.gif";

          img3on = new Image(130,62);
          img3on.src = "gif/newson.gif";

          img4on = new Image(130,62);
          img4on.src = "gif/entryon.gif";


          img1off = new Image(130,62);
          img1off.src = "gif/homeoff.gif";

          img2off = new Image(130,62);
          img2off.src = "gif/caloff.gif";

          img3off = new Image(130,62);
          img3off.src = "gif/newsoff.gif";

          img4off = new Image(130,62);
          img4off.src = "gif/entryoff.gif";




     }

     function imgOn(imgName) {
          if (document.images) {
          document[imgName].src = eval(imgName + "on.src");
     }
}

     function imgOff(imgName) {
          if (document.images) {
               document[imgName].src = eval(imgName + "off.src");
     }
}