var imgs = new Array();

imgs['home'] = new Image();
imgs['home'].src = "home.jpg";
imgs['homeover'] = new Image();
imgs['homeover'].src = "homeover.jpg";

imgs['contact'] = new Image();
imgs['contact'].src = "contact.jpg";
imgs['contactover'] = new Image();
imgs['contactover'].src = "contactover.jpg";

imgs['agency'] = new Image();
imgs['agency'].src = "agency.jpg";
imgs['agencyover'] = new Image();
imgs['agencyover'].src = "agencyover.jpg";

imgs['portfolio'] = new Image();
imgs['portfolio'].src = "portfolio.jpg";
imgs['portfolioover'] = new Image();
imgs['portfolioover'].src = "portfolioover.jpg";

imgs['aboutus'] = new Image();
imgs['aboutus'].src = "aboutus.jpg";
imgs['aboutusover'] = new Image();
imgs['aboutusover'].src = "aboutusover.jpg";

	function el(id) {

	    if (document.getElementById) {
	     return document.getElementById(id);
	    } else if (window[id]) {
	     return window[id];
	    } else if (document.all)
		 return document.all[id];
	     return null;

	}

	function ChangeImage(event,id) {

     var img = el(id)
     if (img) {
      img.src = imgs[id+event].src;
     }
     else return false;

	}