if (document.images)
{
  homeOn = new Image();
  homeOn.src = "images/home_on.gif";
  servicesOn = new Image();
  servicesOn.src = "images/services_on.gif";
  informationOn = new Image();
  informationOn.src = "images/information_on.gif";
  emailOn = new Image();
  emailOn.src = "images/email_on.gif";

  homeOff = new Image();
  homeOff.src = "images/home_off.gif";
  servicesOff = new Image();
  servicesOff.src = "images/services_off.gif";
  informationOff = new Image();
  informationOff.src = "images/information_off.gif";
  emailOff = new Image();
  emailOff.src = "images/email_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");
    }
  }
}