Mendisable Menu Close pada Delphi

Berikut listing programnya :

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls
type
  TForm1 = class(TForm)
    Label1: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
   hMenuHandle : HMENU;
begin
     hMenuHandle := GetSystemMenu(Form1.Handle, FALSE);
     if (hMenuHandle <> 0) then DeleteMenu(hMenuHandle, SC_CLOSE, MF_BYCOMMAND);
end;

end.