contestImage = new Image(); 
contestImage.src = "/contest/2010/images/contest-menu-entry-on.png";
contestImage = new Image(); 
contestImage.src = "/contest/2010/images/contest-menu-rules-on.png";
contestImage = new Image(); 
contestImage.src = "/contest/2010/images/contest-menu-sponsors-on.png";

function roll(img_name, img_src) {
	document[img_name].src = img_src;
}