if (document.images) {

	// nav over images
    img1on = new Image();
    img1on.src = "images/elements/nav/about_on.gif";
    img2on = new Image();
    img2on.src = "images/elements/nav/facilities_on.gif";
    img3on = new Image();
    img3on.src = "images/elements/nav/contract_on.gif";
    img4on = new Image();
    img4on.src = "images/elements/nav/current_on.gif";
    img5on = new Image();
    img5on.src = "images/elements/nav/complete_on.gif";
    img6on = new Image();
    img6on.src = "images/elements/nav/contact_on.gif";

	// nav off images
    img1off = new Image();
    img1off.src = "images/elements/nav/about_off.gif";
    img2off = new Image();
    img2off.src = "images/elements/nav/facilities_off.gif";
    img3off = new Image();
    img3off.src = "images/elements/nav/contract_off.gif";
    img4off = new Image();
    img4off.src = "images/elements/nav/current_off.gif";
    img5off = new Image();
    img5off.src = "images/elements/nav/complete_off.gif";
    img6off = new Image();
    img6off.src = "images/elements/nav/contact_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");
    }
}