>Hi Dan
>
>>This check should be implemented as a business rule as discussed in the "Specifying and Creating Business Rules" in the Developer's Guide.
>
>Thanks for your response. But I must confess I am using CodeBook as my framework and MM being very similar I posted my question here. If I am to put this in the BO can you please let me know if it should be in BeforeSave() BeforeSaveValidation() or the AfterSave() methods and that too before or after the DODEFAULT().
>
>Please advise.

As far as I recall, MereMortals is a bit different in this regard. Usually you create validation methods in the business object and they are validated in CheckRules() method.