title: Session_End in Global.asax.cs not firing using forms authentication
body: <p>I have an asp.net 4.0 application that is using forms authentication set to a timeout at 45 minutes. I would like to redirect the user to a timeout page when the session has expired. Can anyone tell me how to do this? I am running .net 4.0.</p>
  
  <p>web.config has: </p>
  
  <pre><code>&lt;authentication mode="Forms"&gt;
    &lt;forms name=".ASPXAUTH" loginUrl="~/Login.aspx"
      defaultUrl="~/Default.aspx" protection="All" timeout="45"
      requireSSL="false"&gt;
    &lt;/forms&gt;
  &lt;/authentication&gt;
  </code></pre>
  
  <p>Global.asax.cs file has:</p>
  
  <pre><code>void Session_End(object sender, EventArgs e)
  {
      Response.Redirect("~/Timeout.aspx");
  }  
  </code></pre>