if (document.images)
{
  var img = new Image;

  img.src = "images/nav/home_nrm.gif";
  img.src = "images/nav/what_nrm.gif";
  img.src = "images/nav/why_nrm.gif";
  img.src = "images/nav/make_nrm.gif";
  img.src = "images/nav/five_nrm.gif";
  img.src = "images/nav/work_nrm.gif";
  img.src = "images/nav/effect_nrm.gif";
  img.src = "images/nav/contact_nrm.gif";
  img.src = "images/nav/book_nrm.gif";

}

function changeimg(img, name)
{
  if (document.images)
    document.images[name].src=img;
}