if (document.images) {
image1on = new Image();
image1on.src="/img/nav1b.png";

image1off = new Image();
image1off.src = "/img/nav1a.png";

}

if (document.images) {
image2on = new Image();
image2on.src="/img/nav2b.png";

image2off = new Image();
image2off.src = "/img/nav2a.png";

}

if (document.images) {
image3on = new Image();
image3on.src="/img/nav3b.png";

image3off = new Image();
image3off.src = "/img/nav3a.png";

}

if (document.images) {
image4on = new Image();
image4on.src="/img/nav4b.png";

image4off = new Image();
image4off.src = "/img/nav4a.png";

}

if (document.images) {
image5on = new Image();
image5on.src="/img/nav5b.png";

image5off = new Image();
image5off.src = "/img/nav5a.png";

}

if (document.images) {
image6on = new Image();
image6on.src="/img/nav6b.png";

image6off = new Image();
image6off.src = "/img/nav6a.png";

}

if (document.images) {
image7on = new Image();
image7on.src="/img/nav7b.png";

image7off = new Image();
image7off.src = "/img/nav7a.png";

}

if (document.images) {
image8on = new Image();
image8on.src="/img/nav8b.png";

image8off = new Image();
image8off.src = "/img/nav8a.png";

}

function turnOn(imageName) {
if (document.images) {
document[imageName].src = eval(imageName + "on.src");
}
}

function turnOff(imageName) {
if (document.images) {
document[imageName].src = eval(imageName + "off.src");
}
}