[apache] auth. logout? how to "expire" authentication?

[po...@scribble.com]

i am using .htaccess file with apache (on un*x) to require "Basic"
authentication
of a directory. it asks for a username and password. works great.

now, i have a cgi script in my directory, which can tell who the user is
with
the REMOTE_USER environment variable. GREAT again!

but: how can this user *LOG OUT* ?? that is, how can i
cancel/end/expire/revoke
authentication? i can *manually* do this by changing the password for
the user
(or delete the user) and then add it again. but how can i do this from
a cgi script?

my problem is this: i am in an environment where multiple users may be
using the
same machine, and often dont quit the browser. a simple "log out"
button would solve
this problem, if i knew how to cancel the authentication they were
granted.

surely there must be a way to do this, if only a 'trick' or other hack.
it would seem
pretty silly if there werent. i searched the apache doc site to no
avail.
*please* done make me have to have my script change the password to
logout! hehe

THANKS,
-jon
po...@scribble.com