function movePic(img_name,img_src){
  document[img_name].src = img_src;
  navImage();
}

function setPrefix(elmName) {
if (document.getElementById != null) {
return document.getElementById(elmName);
}
if (document.all != null) {
return document.all[elmName];
}
}

function navImage() {
var sPath = window.location.pathname;
var sPage = sPath.slice(sPath.lastIndexOf('/') + 1);
//alert(sPage);
if(sPage == 'home.aspx') {
setPrefix("home").src = '../images/navbar-home-hl.jpg';
}
if(sPage == 'about.aspx') {
setPrefix("about").src = '../images/navbar-about-hl.jpg';
}
if(sPage == 'gallery.aspx') {
setPrefix("gallery").src = '../images/navbar-gallery-hl.jpg';
}
if(sPage == 'products.aspx') {
setPrefix("products").src = '../images/navbar-products-hl.jpg';
}
if(sPage == 'related.aspx') {
setPrefix("related").src = '../images/navbar-related-hl.jpg';
}
if(sPage == 'contact.aspx') {
setPrefix("contact").src = '../images/navbar-contact-hl.jpg';
}
}
//alert(setPrefix('navabout').className);

function overlay(img_src) {
el = document.getElementById("overlay");
el.style.visibility = (el.style.visibility == "visible") ? "hidden" : "visible";
document['displayimage'].src = img_src;
}