session state that is no longer available?

[nbdy9(nospam)]

I have a ASP.Net website (mobile). From time to time the browser popup
the following message. Anyway to catch the error and redirect to my
start page? saying, login.aspx? Thanks.

================================================== =====================
Server Error in '/mobSec' Application.
The page requires session state that is no longer available. Either the
session has expired, the client did not send a valid session cookie, or
the session state history size is too small. Try increasing the history
size or session expiry limit.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.Exception: The page requires session state
that is no longer available. Either the session has expired, the client
did not send a valid session cookie, or the session state history size
is too small. Try increasing the history size or session expiry limit.

Source Error:

An unhandled exception was generated during the execution of the current
web request. Information regarding the origin and location of the
exception can be identified using the exception stack trace below.

Stack Trace:

[Exception: The page requires session state that is no longer available.
Either the session has expired, the client did not send a valid session
cookie, or the session state history size is too small. Try increasing
the history size or session expiry limit.]
System.Web.UI.MobileControls.MobilePage.OnViewStat eExpire(EventArgs e)

System.Web.UI.MobileControls.MobilePage.LoadPageSt ateFromPersistenceMedium()
System.Web.UI.Page.LoadPageViewState()
System.Web.UI.Page.ProcessRequestMain()
Version Information: Microsoft .NET Framework Version:1.1.4322.573;
ASP.NET Version:1.1.4322.573