if (document.images) {
  image1on = new Image();image1on.src = "images/menu/feature-tour-on.gif";
  image2on = new Image();image2on.src = "images/menu/company-on.gif";
  image3on = new Image();image3on.src = "images/menu/support-on.gif";
  image4on = new Image();image4on.src = "images/menu/purchase-on.gif";

  image1off = new Image();image1off.src = "images/menu/feature-tour-off.gif";
  image2off = new Image();image2off.src = "images/menu/company-off.gif";
  image3off = new Image();image3off.src = "images/menu/support-off.gif";
  image4off = new Image();image4off.src = "images/menu/purchase-off.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");
    }
  }
}