private void txtTKGV_TextChanged(object sender, EventArgs e) { if (cbTKGV.Text == "Mã") { dgvGiaoVien.DataSource = tk.TK_Ma_GiaoVien(txtTKGV.Text); } else { dgvGiaoVien.DataSource = tk.TKTenGiaoVien(txtTKGV.Text); } }