anchor.diff:      ImageName := '';
       TabOrder := 9;
       OnClick := @btnDeleteClicked;
  -    Enabled := False;
  +//    Enabled := False;
     end;
   
     btnRetrieve := TfpgButton.Create(self);
  
positive.code:     ImageName := '';
      TabOrder := 7;
      OnClick := @btnAddClicked;
      Enabled := False;
    end;
  
    btnEdit := TfpgButton.Create(self);
  
negative.code: end;
  
  procedure TMainForm.btnAddClicked(Sender: TObject);
  var
    lData: TPerson;
  begin
    lData := TPerson.CreateNew;
    lData.Name := 'New Name';
    lData.Age := 12;
    FList.Add(lData);
  end;
  
  procedure TMainForm.btnEditClicked(Sender: TObject);
  begin
    if medGrid.SelectedObject = nil then
      Exit;
    EditPerson(TPerson(medGrid.SelectedObject));
  end;
  
  procedure TMainForm.btnDeleteClicked(Sender: TObject);
  begin
    medGrid.SelectedObject.Deleted := True;
    FList.NotifyObservers;
  end;
  
  procedure TMainForm.btnUpdateClicked(Sender: TObject);
  