onload = function() 
{
images = new Array("ONSITE/imgs/1.jpg", "ONSITE/imgs/2.jpg", "ONSITE/imgs/3.jpg", "ONSITE/imgs/4.jpg", "ONSITE/imgs/5.jpg", "ONSITE/imgs/6.jpg", "ONSITE/imgs/7.jpg", "ONSITE/imgs/8.jpg");

rand = Math.floor(Math.random()*images.length);

imagen = images[rand];

document.body.style.background = "url("+imagen+") no-repeat fixed center center";

}
// JavaScript Document