[sorockinalex]

А было так. Изменённое. Работает! Спасибо!

Код:

procedure TFAddEquipmentNumbers.FormCreate(Sender: TObject);
begin
  LoadFormProperties(Self as TForm);

  SetLength(numberEdit,1);
  SetLength(birthyearEdit,1);

  NumberEdit[0]:=TEdit.Create(Self);
  NumberEdit[0].Parent:=Self;
  NumberEdit[0].Left:=8;
  NumberEdit[0].Top:=69;
  NumberEdit[0].Width:=60;
  NumberEdit[0].Height:=21;
  NumberEdit[0].Visible:=true;
  NumberEdit[0].Enabled:=true;
  NumberEdit[0].OnKeyPress:=EditKeyPress;

  birthyearEdit[0]:=TEdit.Create(Self);
  birthyearEdit[0].Parent:=Self;
  birthyearEdit[0].Left:=76;
  birthyearEdit[0].Top:=69;
  birthyearEdit[0].Width:=30;
  birthyearEdit[0].Height:=21;
  birthyearEdit[0].MaxLength:=2;
  birthyearEdit[0].Visible:=true;
  birthyearEdit[0].Enabled:=true;
  birthyearEdit[0].OnKeyPress:=EditKeyPress;

  try ApplyImage.Picture.LoadFromFile('icons\apply.ico');
  except showmessage('Íå íàéäåíà èêîíêà apply.ico') end;
  try CloseImage.Picture.LoadFromFile('icons\close.ico');
  except showmessage('Íå íàéäåíà èêîíêà close.ico') end;

end;

Код:

procedure TFAddEquipmentNumbers.EditKeyPress(Sender: TObject; var Key: Char);
const
  allowedsymbols: set of Char=['0'..'9'];
begin
  if (Key in allowedsymbols) then
  begin
  end
  else key :=#0;
end;