function init(){

	wall = new Array();

	wall[0] = "img/top_image1.jpg";

	wall[1] = "img/top_image2.jpg";

	wall[2] = "img/top_image3.jpg";

	rnd = Math.round(Math.random() * (wall.length - 1));

	document.images["topimage"].src = wall[rnd];

}