[AccessD] matching field error

Hello Group,

i get the following error in a form, when i close it and the field 'PrTestID' is empty:

The microsoft Jet database engine cannot find a record in table 'tblTest' with key matching field(s) 'PrTestID'


How is this possible, because the field isn't required?
Al the ID fields in the form give the same error when they are empty (and all aren't reqiured).



Pedro Janssen