procedure TForm1.Menu1Click(Sender: TObject);
begin
if HiWord(GetKeyState(VK_SHIFT)) <> 0 then
Label1.Caption := 'Shift'
else
if HiWord(GetKeyState(VK_CONTROL)) <> 0 then
Label1.Caption := 'Control'
else
if HiWord(GetKeyState(VK_MENU)) <> 0 then
Label1.Caption := 'Alt'
else
Label1.Caption := 'None';
end;