Code:
procedure TForm1.Edit2KeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
var
Smer: Integer;
begin
if key in [VK_UP,VK_DOWN] then
begin
if Key = VK_UP then Smer := 1
else if Key = VK_DOWN then Smer := 0;
PostMessage(Handle, WM_NEXTDLGCTL, Smer, 0);
end;
end;