$(document).ready(function(){
   var height = screen.height;
   var width = screen.width;
   var start = history.length;
   var ref = document.referrer;
   var lang = navigator.systemLanguage;

   var xmlHttp;
   
   try
   {  // Firefox, Opera 8.0+, Safari
      xmlHttp=new XMLHttpRequest();
   }
   catch (e)
   {  // Internet Explorer
      try
      {    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");    }
      catch (e)
      {
         try
         {      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");      }
         catch (e)
         {          return false;      }
      }
   }
   
   xmlHttp.onreadystatechange=function()
   {
      if(xmlHttp.readyState==4)
      {
         // do nothing
      }
    }

   xmlHttp.open("GET", "/reg.php?visit_id="+ visit_id +"start="+ start +"&width="+ width +"&height="+ height +"&ref="+ escape(ref) +"&lang="+ lang +"",true);
   xmlHttp.send(null);

});