Return to the defult user

From: Imad (
Date: 02/09/04

Date: Mon, 9 Feb 2004 06:47:05 -0800

Could anyone remind me how can I return the user profile to
the defult user profile once the user logs off so all the
changes he or she make to the profile will be deleted
especialy if the user has access to the internet so all the
cookies and the history will be deleted automaticly once
the user logs off..