function swapImage() {
theImages = new Array("banner02.jpg", "banner03.jpg", "banner04.jpg", "banner05.jpg", "banner06.jpg", "banner07.jpg", "banner08.jpg", "banner09.jpg", "banner10.jpg", "banner11.jpg", "banner12.jpg");
whichImage = Math.floor(Math.random()*theImages.length);
document.write('<IMG SRC="' +theImages[whichImage]+ '">');

}