[NumLock]

Код:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    procedure Timer1Timer(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  TLabel(Components[0]).Visible:=not TLabel(Components[0]).Visible;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  with TLabel.Create(Self) do
  begin
    Parent:=Self;
    Caption:='TLabel';
  end;
  with TTimer.Create(Self) do
  begin
    Interval:=250;
    OnTimer:=Timer1Timer;
  end;
end;

end.