[Zope-dev] how can I prevent undo?

Hi there, I have objects that are linked to an external database. When they are deleted, also the data in the external database is deleted. Now an undo is bad, because I then get an object with ab link to non existing data. I must therefore prevent undo. How can I do that? Thanks, Robert -- mit freundlichen Grüssen Robert Rottermann www.redCOR.ch