if (document.images)  {
            img1on = new Image ();    img1on.src = "img/mphilo.jpg";
            img2on = new Image ();    img2on.src = "img/mservo.jpg";
            img3on = new Image ();    img3on.src = "img/mprodo.jpg";

            img1off = new Image ();    img1off.src = "img/mphil1.jpg";
            img2off = new Image ();    img2off.src = "img/mserv1.jpg";
            img3off = new Image ();    img3off.src = "img/mprod1.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");
            }
            }