How can I redirect the page when time out happens in asp.net.

Hi Every one,

I am having a Asp.net web Application.

I want to embed the time out functionality in my Application.

i.e If no activity is done I want to redirect when time out happens.

So I have added the code in the web config.

<sessionState timeout="10"></sessionState>

And In my Global.ascx at the

   void Session_End(object sender, EventArgs e)

        {

            Response.Redirect("~/Expired.aspx",false);

//Error Msg {"Response is not available in this context."}

          HttpContext.Current.Response.Redirect("~/Expired.aspx");

//Error Msg Object referenced to a null.  }

I am not sure what wrong in my code.

Any suggestions Pls.