images = new Array(2);

images[0] = "<a href = 'http://america-store.stores.yahoo.net/2for20obcoho.html'><img src='http://lib.store.yahoo.net/lib/america-store/Marcos' alt='Random Customer'></a>";

images[1] = "<a href = 'http://america-store.stores.yahoo.net/fbiknitcap.html'><img src='http://lib.store.yahoo.net/lib/america-store/Page' alt='Random Customer'></a>";

index = Math.floor(Math.random() * images.length);
document.write(images[index]);