Hi!
I've created a session with a variable calles $access. This variable contains "granted" or "denied". When the user logged out, i write "denied" in the variable. So he can't get back.
I've tried to destroy the session, but that hasn't worked properly. In that case, the user can go back with the browsers back-button.
Try www.reformnet.de and try "buying" some things. You must authentificate yourself in the customerarea. Have no fear, no articles will be delivered, it's my exam-project.