if (document.images) {
but01n = new Image();
but01n.src = "images/mainnav_home.png";
but02n = new Image();
but02n.src = "images/mainnav_about.png";
but03n = new Image();
but03n.src = "images/mainnav_services.png";
but04n = new Image();
but04n.src = "images/mainnav_news.png";
but05n = new Image();
but05n.src = "images/mainnav_contact.png";

butOff = new Image();
butOff.src = "images/spacer.gif";
}

function ShowHide(imgDocID,imgObjName) {
if (document.images) 
  document.images[imgDocID].src = eval(imgObjName + ".src")
}