if (document.images) {
img1 = new Image();
img1.src = "images/rightback.png";
img2 = new Image();
img2.src = "images/leftback.png";
img3 = new Image();
img3.src = "images/botback.png";
img4 = new Image();
img4.src = "images/ll_corner.png";
img5 = new Image();
img5.src = "images/lr_corner.png";

}

function linkOn(num)
{
document.images['link' + (num)].src = "images/link"+(num)+"a.gif"
}

function linkOff(num)
{
document.images['link' + (num)].src = "images/link"+(num)+".gif"
}