// JavaScript Document
			var imagenes = new Array(); 
			imagenes[0] = "/images/img4.jpg"; 
			imagenes[1] = "/images/img3.jpg"; 
			imagenes[2] = "/images/img2.jpg"; 
			imagenes[3] = "/images/img1.jpg";
			document.getElementById("logo1").style.background = "url("+imagenes[parseInt(Math.random()*4)]+") no-repeat top left";