protected void result_grid_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.BID_field.Value = result_grid.SelectedRow.Cells[0].Text;

            bm.BrID = int.Parse(this.BID_field.Value);

            if (rt.return_book(bm) && bd.BorrowCount_decrement(bm) && bd.Available_copies_increment(bm))
            {
                this.msg_lbl.Text = "Returned";
                databinding(uid_field.Value.ToString());
            }
        }