Как программно определить количество кнопок мышки

Code:

// if the result is 0, no mouse is present

function GetNumberOfMouseButtons: Integer;

begin

  Result := GetSysTemMetrics(SM_CMOUSEBUTTONS);

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

  ShowMessage('Your mouse has ' + IntToStr(GetNumberOfMouseButtons) + ' buttons.');

end;