if (document.images) {
  Homeon = new Image(); Homeon.src = "images/Home_on.jpg"; Homeoff = new Image(); Homeoff.src = "images/Home.jpg";
  Catalogon = new Image(); Catalogon.src = "images/Catalog_on.jpg"; Catalogoff = new Image(); Catalogoff.src = "images/Catalog.jpg";
  AboutUson = new Image(); AboutUson.src = "images/AboutUs_on.jpg"; AboutUsoff = new Image(); AboutUsoff.src = "images/AboutUs.jpg";
  ULinkson = new Image(); ULinkson.src = "images/ULinks_on.jpg"; ULinksoff = new Image(); ULinksoff.src = "images/ULinks.jpg";
  Finduson = new Image(); Finduson.src = "images/Findus_on.jpg"; Findusoff = new Image(); Findusoff.src = "images/Findus.jpg";
  Calendaron = new Image(); Calendaron.src = "images/Calendar_on.jpg"; Calendaroff = new Image(); Calendaroff.src = "images/Calendar.jpg";
  Contacton = new Image(); Contacton.src = "images/Contact_on.jpg"; Contactoff = new Image(); Contactoff.src = "images/Contact.jpg";

  } 
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");
    }
  }
}