jQuery().ready(function() {

   
   startChange();
    
    
   
    
    
});

    var randomNo;
    var i;

    function changeImage()
    {
    
    
      randomNo = Math.floor(Math.random()*4);
    
       jQuery('#banner').css("background-image","url(http://www.skbrickwork.co.uk/site/wp-content/themes/thematic/library/img/banner"+randomNo+".jpg)");
     setTimeout('startChange()', 5000);
   
    
     
  }
    
    
     function startChange()
     {

      if(jQuery('#banner').length>0){
      
        setTimeout('changeImage()', 5000);
      
      }
    
    }