var theImages=['front_image3','front_image6','front_image7','front_image8','front_image9','front_image10'];
			var p = theImages.length;
			var whichImage = Math.round(Math.random()*(p-1));
			onload=function() {
				document.getElementById('picture_window').style.background="url(images/"+theImages[whichImage]+".jpg) no-repeat";
			}