public void EditGiaoVien(EDIT_MODE edit)
        {
            DataRow drNew;

            if (edit == EDIT_MODE.SUA)
            {
                int idxNew = idxGV;
                drNew = dtGiaoVien.NewRow();
                oBGiaoVien.ToDataRow(pGiaoVienInfo, ref drNew);
                DataRow dr = grvGiaoVien.GetDataRow(idxGV);
                dtGiaoVien.Rows.InsertAt(drNew, idxNew + 1);
                dtGiaoVien.Rows.Remove(dr);
                grvGiaoVien.FocusedRowHandle = idxNew;
            }
            else
            {
                drNew = dtGiaoVien.NewRow();
                oBGiaoVien.ToDataRow(pGiaoVienInfo, ref drNew);
                dtGiaoVien.Rows.Add(drNew);
            }
        }