[Zope] User logout

Hello! Anybody know how to programically implement user logOUT? Is it something like (not tested yet): set "anonymous", uses Zope API; then forward him to login form? I would like to logout, then press "<=" back button into the browser and get access denied, but not be still logged in. If somebody understands my broken english, please answer. ;-) -- Microsoft merges technologoies: Windows CE + Windows ME + Windows NT = Windows CEMENT Sincerely yours, Bogdan M.Maryniuck