title: count number of sessions in ASP.net/c#
body: <p>I need to count number of sessions but it dose not work when I say if numbers of sessions are 2 then do something.  The example below is my code:</p>
  
  <pre><code>  // count curent session in order to keep two player
    if (HttpContext.Current.Session.Count == 2)
    {
       Response.Redirect("update.aspx");
    }
  </code></pre>
  
  <p>I place the above code in code behind.  is there any other way that I can say: if number of sessions are 2 else do something... </p>