At 11:59 AM 4/08/2007, you wrote:

>Thanks Helen,
> it seems to work at first, but only if I don't select a different
>line in the master grid. Once you do, the same error occurs. This is
>what I tried on my simple test form....
>
>//---------------------------------------------------------------------------
>void __fastcall TForm1::Button1Click(TObject *Sender)
>{
> if (IBOQuery2->Active)
> IBOQuery2->Close();
> IBOQuery2->SQL->Clear();
> IBOQuery2->DataSource = NULL;

Don't you have Nil in C++? "NULL" doesn't look right to me, at least
from the POV of ObjectPascal....Nil means "nothing assigned". NULL
means something different to me...

Helen