procedure TfKustomer.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if (Key = VK_DOWN) or (Key = VK_RETURN) then
    begin
      SendMessage(Handle,WM_NEXTDLGCTL,0,0);
    end
  else
    if Key = VK_UP then
      begin
        SendMessage(Handle,WM_NEXTDLGCTL,-1,0);
      end;
end;

Key = VK_DOWN
Key = VK_RETURN
Key = VK_UP

	procedure TfKustomer.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if (Key = VK_DOWN) or (Key = VK_RETURN) then
    begin
      SendMessage(Handle,WM_NEXTDLGCTL,0,0);
    end
  else
    if Key = VK_UP then
      begin
        SendMessage(Handle,WM_NEXTDLGCTL,-1,0);
      end;
end;

procedure TfKustomer.FormKeyDown(Sender: TObject; var Key: Char);
begin
  if (Key =#28)or (Key =#13)then
    begin
      SendMessage(Handle,WM_NEXTDLGCTL,0,0);
    end
  else
    if Key =#26then
      begin
        SendMessage(Handle,WM_NEXTDLGCTL,-1,0);
      end;
end;

procedure TfKustomer.FormKeyDown(Sender: TObject; var Key: Char);
begin
  if (Key = chr(VK_DOWN)) or (Key = chr(VK_RETURN)) then
    begin
      SendMessage(Handle,WM_NEXTDLGCTL,0,0);
      key :=#0; { <--- ilangin suarane }
    end
  else
    if Key = chr(VK_UP)then
      begin
        SendMessage(Handle,WM_NEXTDLGCTL,-1,0);
        key :=#0;  { <--- ilangin beep ne }
      end;
end;