if (document.images) {
            img1on = new Image();
            img1on.src = "images/nav/homeOn.gif";
            img2on = new Image();
            img2on.src = "images/nav/aboutOn.gif";
            img3on = new Image();
            img3on.src = "images/nav/photoGalleryOn.gif";
            img4on = new Image();
            img4on.src = "images/nav/constructionOn.gif";
            img5on = new Image();
            img5on.src = "images/nav/contactOn.gif";

            img1off = new Image();
            img1off.src = "images/nav/homeOff.gif";
            img2off = new Image();
            img2off.src = "images/nav/aboutOff.gif";
            img3off = new Image();
            img3off.src = "images/nav/photoGalleryOff.gif";
            img4off = new Image();
            img4off.src = "images/nav/constructionOff.gif";
            img5off = new Image();
            img5off.src = "images/nav/contactOff.gif";
 
      
        }

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");
        }
}