[Zope] Override members values

Hi all! I need to override the value of some members of my product I think the correct way was __getattr__ function but I read some list's messages telling to use __getattr__ only if you don't have other way How can I override only the value of some dynamic members? I call dynamic members to the members that the user adds (with a property or an object) Why? Because I would like things like: Object.member1 -> 1 (if you are a manager) Object.member1 -> 2 (if you are a normal user) or Object.member1 -> 1 (for firefox users) Object.member1 -> 2 (for ie users) Where member1 is a property at property manager (for example) Thank so much! -- Mis Cosas http://blogs.sistes.net/Garito