unauthentication

[Jonas Nordström]

We have implemented an intranet gateway in mod-perl, where external clients
are authenticated against our NT-domain, that works fine.
I want to add the possibility to "log-out", ie, to "de-authenticate" the
user, so that the next time he tries to access the gateway, he will be
prompted to convey username/password.
Is that possible? Is it enough to respond with a "401"-page?

/Jonas