Have you set up some sort of password control for your site? If not then see the previous answer. If you have then it all depends on the software that you have used to control access.
Thanks for the response. I am using Bravenet's Password Protection for users to signon. I also use their code to protect every page. I am using MS Frontpage. I guess what I was asking was for some code to be used as a logoff code so I could send the user to an exit page and at the same time delete or inhibit their Logon and Password so someone else couldn't get back into the system.