php htaccess logins and logouts

Hi all, I've got a site set up that is using an htaccess file to provide secure access to a directory. That is working fine. What I wondered was, is there a way to log out via PHP. As I understand it, the login mechanism is part of Apache, so I guess what I'm really asking is, is there a way that I can get Apache to end the 'session' that Apache has set up, using PHP? I'm sure I've seen cPanel do it, so I was wondering how easy this would be to do myself. Thanks, Ash http://www.ashleysheridan.co.uk