if (document.images) {
  image1on = new Image();
  image1on.src = "navbutns/bt_home_on.gif";
  
  image2on = new Image();
  image2on.src = "navbutns/bt_news_on.gif";
  
  image3on = new Image();
  image3on.src = "navbutns/bt_services_on.gif";
  
  image4on = new Image();
  image4on.src = "navbutns/bt_careers_on.gif";
  
  image5on = new Image();
  image5on.src = "navbutns/bt_bookings_on.gif";
  
  image6on = new Image();
  image6on.src = "navbutns/bt_store_on.gif";
  
  image7on = new Image();
  image7on.src = "navbutns/bt_quick_ideas_on.gif";
  
  image8on = new Image();
  image8on.src = "navbutns/bt_contact_on.gif";
      
  image1off = new Image();
  image1off.src = "navbutns/bt_home_off.gif";
  
  image2off = new Image();
  image2off.src = "navbutns/bt_news_off.gif";
  
  image3off = new Image();
  image3off.src = "navbutns/bt_services_off.gif";
  
  image4off = new Image();
  image4off.src = "navbutns/bt_careers_off.gif";
  
  image5off = new Image();
  image5off.src = "navbutns/bt_bookings_off.gif";
  
  image6off = new Image();
  image6off.src = "navbutns/bt_store_off.gif";
  
  image7off = new Image();
  image7off.src = "navbutns/bt_quick_ideas_off.gif";
  
  image8off = new Image();
  image8off.src = "navbutns/bt_contact_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");
    }
  }
}