How can I treat an EDBEditError Exception?

[FabioAvallone]

I have a Query field with the mask '999.999.999-99' (for a document). I also have a routine that tests if the document is valid or not, based in the brasilian rules. The user digits the document number in the DBEdit. If the user tapes the complete number (Ex.: 123.456.789-12) and the document is valid, the program goes ahead. If it isn´t valid, it shows an error message and return the focus to this DBEdit.
The error that is occurring is:
- if the user digits the complete number and it is invalid (but it´s ok);
- if the number is invalid (it´s ok too);
* if the user digits something like this '123.456.___-__', then the error occurs. (when the user let it incompleted).

The exception kind is EDBEditError, but I can´t treat it with "Try...except". The error occurs BEFORE the commands in the except statements and BEFORE onExit event too.

I´d like to thank you
See ya!