Detecting ASP.NET Session Timeouts

public class basePageSessionExpire : System.Web.UI.Page
{
public basePageSessionExpire()
{
}

override protected void OnInit(EventArgs e)
{
base.OnInit(e);

if (Context.Session != null)
{

if (Session.IsNewSession)
{
string szCookieHeader = Request.Headers[“Cookie”];
if ((null != szCookieHeader) && (szCookieHeader.IndexOf(“ASP.NET_SessionId”) >= 0))
{
Response.Redirect(“sessionTimeout.htm”);
}
}
}
}
}