if (document.images) {
  		image1on = new Image();
  		image1on.src = "images/navs/electrical_on.gif";
  		image2on = new Image();
  		image2on.src = "images/navs/data_on.gif";
  		image3on = new Image();
  		image3on.src = "images/navs/custom_on.gif";
		image4on = new Image();
  		image4on.src = "images/navs/building_on.gif";
  		image5on = new Image();
  		image5on.src = "images/navs/hydro_on.gif";
  		image1off = new Image();
  		image1off.src = "images/navs/electrical.gif";
  		image2off = new Image();
  		image2off.src = "images/navs/data.gif";
 		image3off = new Image();
  		image3off.src = "images/navs/custom.gif";
		image4off = new Image();
  		image4off.src = "images/navs/building.gif";
  		image5off = new Image();
  		image5off.src = "images/navs/hydro.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");
    			}
  			}
		}