if (document.images) {
	img1on = new Image();            // Active images
	img1on.src = "images/header_b2.jpg";
	img2on = new Image();
	img2on.src = "images/header_c2.jpg";
	img3on = new Image();
	img3on.src = "images/header_e2.jpg";
	img1off = new Image();            // Inactive images
	img1off.src = "images/header_b.jpg"; 
	img2off = new Image();
	img2off.src = "images/header_c.jpg";
	img3off = new Image();
	img3off.src = "images/header_e.jpg";

        
  }
    function imgOn(imgName) {
            if (document.images) {
                document[imgName].src = eval(imgName + "on.src");
            }
    }
    function imgOff(imgName) {
            if (document.images) {
                document[imgName].src = eval(imgName + "off.src");        
            }
    }