var rand1 = 0;
var useRand = 0;

images = new Array;
images[1] = new Image();
images[1].src = "images/ads/adMercury.jpg";
images[2] = new Image();
images[2].src = "images/ads/adMySpace.jpg";
images[3] = new Image();
images[3].src = "images/ads/adMySpaceMusic.jpg";
images[4] = new Image();
images[4].src = "images/ads/adPuzzle.jpg";
images[5] = new Image();
images[5].src = "images/ads/adSingles.jpg";
images[6] = new Image();
images[6].src = "images/ads/adSSL.jpg";
images[7] = new Image();
images[7].src = "images/ads/adTimeWarner.jpg";
images[8] = new Image();
images[8].src = "images/ads/adVontage.jpg";

function swapPic() 
{
    var imgnum = images.length - 1;
    do 
    {
        var randnum = Math.random();
        rand1 = Math.round((imgnum - 1) * randnum) + 1;
    } while (rand1 == useRand);
    
    useRand = rand1;
    document.randimg.src = images[useRand].src;
}