procedure TForm1.DBCedula2Exit(Sender: TObject);
begin
with DataModule1.qCedula2 do
try
Close;
ParamByName('PCEDULA').AsString := DBCedula2.Text;
Open;
if not isEmpty then
begin
MessageBox(Self.Handle, 'Cédula existente', '', MB_ICONERROR + MB_OK);
DBEdit1.SetFocus;
Abort
end
finally
Close
end;
end;