Windows re-authentication in ASP.NET using C# after session timeout

[Freddie]

Good day,

We have developed an intranet site for one of our clients. We are
using Windows Authentication successfully. Our problem lies in the
re-authentication after we raise a session timeout. Because windows
already authenticated the user, the site just continues as usual. The
only way at this point to re-authenticate the user is to close IE and
open it again.

What would be the correct way to de-authenticate and re-authenticate
the user without shutting down IE.

Thanx,
Freddie