if (document.images) {
   homeOn = new Image();
   homeOn.src = "images/home-on.gif";
   homeOff = new Image();
   homeOff.src = "images/home-off.gif";
   }

if (document.images) {
   teamOn = new Image();
   teamOn.src = "images/meet-the-team-on.gif";
   teamOff = new Image();
   teamOff.src = "images/meet-the-team-off.gif";
   }

if (document.images) {
   feedbackOn = new Image();
   feedbackOn.src = "images/client-feedback-on.gif";
   feedbackOff = new Image();
   feedbackOff.src = "images/client-feedback-off.gif";
   }

if (document.images) {
   aboutOn = new Image();
   aboutOn.src = "images/about-us-on.gif";
   aboutOff = new Image();
   aboutOff.src = "images/about-us-off.gif";
   }

if (document.images) {
   contactOn = new Image();
   contactOn.src = "images/contact-us-on.gif";
   contactOff = new Image();
   contactOff.src = "images/contact-us-off.gif";
   }

if (document.images) {
   callbackOn = new Image();
   callbackOn.src = "images/callback-on.gif";
   callbackOff = new Image();
   callbackOff.src = "images/callback-off.gif";
   }
function activate(image_name) {
   if (document.images) {
       document[image_name].src = eval(image_name + "On.src");
   }
   }

function deactivate(image_name) {
   if (document.images) {
       document[image_name].src = eval(image_name + "Off.src");
   }
}