function changeImages() {
	var images = ['tenis_court.jpg','pasture.jpg', 'brick_wall.jpg'];
	var rand = Math.floor(Math.random() * images.length);
	$('#page-image').html('<img src="_images/' +  images[rand]  + '" width="187" height="187" alt="" />');
}
$(document).ready(function() {
   changeImages();
 });