if (document.images) {

  image1on = new Image();
  image1on.src = "graphics/link_1on.gif";

  image2on = new Image();
  image2on.src = "graphics/link_2on.gif";

  image3on = new Image();
  image3on.src = "graphics/link_3on.gif";

  image4on = new Image();
  image4on.src = "graphics/link_4on.gif";

  image5on = new Image();
  image5on.src = "graphics/link_5on.gif";

  image6on = new Image();
  image6on.src = "graphics/link_6on.gif";


  image1off = new Image();
  image1off.src = "graphics/link_1off.gif";

  image2off = new Image();
  image2off.src = "graphics/link_2off.gif";

  image3off = new Image();
  image3off.src = "graphics/link_3off.gif";

  image4off = new Image();
  image4off.src = "graphics/link_4off.gif";

  image5off = new Image();
  image5off.src = "graphics/link_5off.gif";

  image6off = new Image();
  image6off.src = "graphics/link_6off.gif";

}

function changeImages() {
  if (document.images) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = eval(changeImages.arguments[i+1] + ".src");
    }
  }
}