public static ArrayList Nhap(String Ghi_chu)
    {
        ArrayList kq = new ArrayList();
        String    Chuoi;

        do
        {
            Chuoi = XL_CHUOI.Nhap(Ghi_chu);
        } while (!Kiem_tra(Chuoi));
        String[] M = Chuoi.Split(new char[] { Ky_tu_phan_cach });
        for (int i = 0; i < M.Length; i++)
        {
            kq.Add(XL_PHAN_SO.Tao(M[i]));
        }
        return(kq);
    }