//var imagesRan = new Array("images/hero_images/image1.jpg", "images/hero_images/image2.jpg", "images/hero_images/image3.jpg");
jQuery().ready(function(){	
$("#image").css("background-image","url(images/hero_images/image"+[Math.round(Math.random()*13)+1]+".jpg)");
//$('#main').css({
//"background-image" : "url("+imagesRan[Math.round(Math.random())*2]+")",
//});
});