> I have a form with two levels of the subforms on the tab controls. When a
> user tries to enter data in a subform before creating a record in a parent
> form, an error occurs. I want to trap this error in the subform's On Error
> event and undo the data entry, but Me.Undo does not work. I set a Response
> parameter to 0. May be I have to use another value for this parameter? It
is
> not described in Help (Access 2002).

> Thanks.

> I use something like this in the subforms Form_BeforeInsert event:

> If IsNull(Forms!MainForm!PrimaryKey) Then
>     MsgBox "something"
>     Cancel = True
> End If

> In this case the primary key is an autonumber but it ought to work even if
> your primary key is not an autonumber

> Jan

> > I have a form with two levels of the subforms on the tab controls. When
a
> > user tries to enter data in a subform before creating a record in a
parent
> > form, an error occurs. I want to trap this error in the subform's On
Error
> > event and undo the data entry, but Me.Undo does not work. I set a
Response
> > parameter to 0. May be I have to use another value for this parameter?
It
> is
> > not described in Help (Access 2002).

> > Thanks.