private void ShowData()
        {
            BindingSource src = new BindingSource();

            src.DataSource       = NhanVienController.GetLuongNV();
            dataLuong.DataSource = src;

            dataLuong.Columns[2].Visible  = false;
            dataLuong.Columns[3].Visible  = false;
            dataLuong.Columns[4].Visible  = false;
            dataLuong.Columns[5].Visible  = false;
            dataLuong.Columns[6].Visible  = false;
            dataLuong.Columns[7].Visible  = false;
            dataLuong.Columns[10].Visible = false;
            dataLuong.Columns[11].Visible = false;
            dataLuong.Columns[12].Visible = false;
        }