>...all you have to do is have the Valid() event of a control talk to the rules object and just call that one method. Then you have the interface validating data using the exact same code used by the business object.

I thought about this, but then you would be coupling your form and the bizrules object quite tightly.

I was toying with the idea of creating a method simmilar to CheckRules, but to which I would pass the name of the field I'm validating and it would take care of calling the right validation method.

Alex