Как запретить перемещение формы?

type
  TyourForm = class(TForm)
  private
    { Private declarations }
    procedure WMNCHitTest(var Message: TWMNCHitTest); message WM_NCHITTEST;
  end;

procedure TyourForm.WMNCHitTest(var Message: TWMNCHitTest);
begin
  inherited;

  with Message do
    if Result = HTCAPTION then
      Result := HTNOWHERE;
end;