Какой код клавиши??

[KBO]

Доброе всем время суток,
а подскажите, почему все работает кроме кода "123", это - "F12"?

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

const
    ID = WM_USER + 1;

type
  Tform_Test = class(TForm)
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    procedure WM_HotKey(var Message:TMessage); message WM_HOTKEY;
  public
    { Public declarations }
  end;

var
  form_Test: Tform_Test;

implementation

{$R *.dfm}

procedure Tform_Test.FormCreate(Sender: TObject);
begin
  RegisterHotKey(Handle, 112, 0, 112); //for "Hot key" = "F1"
  RegisterHotKey(Handle, 113, 0, 113); //for "Hot key" = "F2"
  RegisterHotKey(Handle, 121, 0, 121);
  RegisterHotKey(Handle, 122, 0, 122);
  RegisterHotKey(Handle, 123, 0, 123); //for "Hot key" = "F12"
end;

procedure Tform_Test.FormDestroy(Sender: TObject);
begin
  UnregisterHotKey(Handle, 50);
  UnregisterHotKey(Handle, 112);
  UnregisterHotKey(Handle, 113);
  UnregisterHotKey(Handle, 121);
  UnregisterHotKey(Handle, 122);
  UnregisterHotKey(Handle, 123);
end;

procedure Tform_Test.WM_HotKey(var Message:TMessage);
begin
  case Message.WParam  of
    50: showmessage('key is push "2"');
    112: showmessage('key is push "F1"');
    113: showmessage('key is push "F2"');
    121: showmessage('key is push "F10"');
    122: showmessage('key is push "F11"');
    123: showmessage('key is push "F12"');
  end;
end;

end;

end.

Хотя если для "F12" использовать следующий код:

procedure Tform_Test.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if key = VK_F12 then
    showmessage('key is push "F12"');
end;

все работает, аж бегом