if (document.images) {
    img1on = new Image(); 
    img1on.src = "images/nav/mouseover_on.gif";

    img1off = new Image(); 
    img1off.src = "images/nav/mouseover_off.gif";
    img2on = new Image(); 
    img2on.src = "images/nav/mouseover_on.gif";

    img2off = new Image(); 
    img2off.src = "images/nav/mouseover_off.gif";
    img3on = new Image(); 
    img3on.src = "images/nav/mouseover_on.gif";

    img3off = new Image(); 
    img3off.src = "images/nav/mouseover_off.gif";
    img4on = new Image(); 
    img4on.src = "images/nav/mouseover_on.gif";

    img4off = new Image(); 
    img4off.src = "images/nav/mouseover_off.gif";
	img5on = new Image(); 
    img5on.src = "images/nav/mouseover_on.gif";

    img5off = new Image(); 
    img5off.src = "images/nav/mouseover_off.gif";
    img6on = new Image(); 
    img6on.src = "images/nav/mouseover_on.gif";

    img6off = new Image(); 
    img6off.src = "images/nav/mouseover_off.gif";
    img7on = new Image(); 
    img7on.src = "images/nav/mouseover_on.gif";

    img7off = new Image(); 
    img7off.src = "images/nav/mouseover_off.gif";
    img8on = new Image(); 
    img8on.src = "images/nav/mouseover_on.gif";

    img8off = new Image(); 
    img8off.src = "images/nav/mouseover_off.gif";
	img9on = new Image(); 
    img9on.src = "images/nav/mouseover_on.gif";

    img9off = new Image(); 
    img9off.src = "images/nav/mouseover_off.gif";
	img10on = new Image(); 
    img10on.src = "images/nav/mouseover_on.gif";

    img10off = new Image(); 
    img10off.src = "images/nav/mouseover_off.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");
       }
}