procedure TForm1.Button1Click(Sender: TObject);
begin
SendMessage(DateTimePicker1.Handle, WM_SYSKEYDOWN, VK_DOWN, 0);
end;
procedure TForm1.Button2Click(Sender: TObject);
begin
DateTimePicker1.Setfocus;
keybd_event(VK_F4,0,0,0);keybd_event(VK_F4,0,KEYEVENTF_KEYUP,0)end;