[jQuery] Appending URL and Session variables to redirect script

[Mintyman]

Hi,

I'm pretty new to using Jquery and javascript and don't quite know how
to do something pretty simple.

I have the following script that I am trying to build that will load
another page in the background when a link is clicked. However, I
don't know the syntax to set the CompanyID and UserID variables. I've
tried everything!!!

The CompanyID should come from a URL variable e.g. 
www.mysite.com/mypage.asp?CompanyID=1064
The UserID will come from a session variable : Session("UserID")

Can anyone help me?

//track download clicks
$(document).ready(function() {
$("a.adtrack").click(function(){

    //Create variables
    var CompanyID = ;
    var UserID = ;
        var DownloadID = $("a.adtrack").attr("name");

$.ajax({
   type: "GET",
   url: "downloadtrack.asp",
   data: "CompanyID=" + CompanyID + "&UserID=" + UserID +
"&DownloadID=" + DownloadID
  });
 });
});