[Zope] Properties in a ZClass

OK, second try: I want users to add their own properties to a ZClass. How exactly do I do that? In a property sheet? How do I get the "Add" button visible in ZClass instance property sheet? Thanks. -- Lars Heber, mailto:Lars.Heber@t-systems.de T-Systems, debis Systemhaus GEI GmbH, Geschaeftsstelle Sachsen