// JavaScript Document
var upperLimit = 3;
var imageRootName ="/images/header/header_bg-";
var imageNumber = Math.floor(Math.random()*upperLimit);
var imageFullName= imageRootName + imageNumber + ".jpg";

function init() {
var theURL = "url(" + imageFullName + ")";
//alert("theURL"+theURL);
document.getElementById('header').style.backgroundImage=theURL;
return;
}
window.onload = init;