private void cmbSoPhong_SelectedIndexChanged(object sender, EventArgs e) { try { if (cmbSoPhong.SelectedValue != null) { Phong objPHong = Phong.GetPhong(int.Parse(cmbSoPhong.SelectedValue + "")); if (objPHong != null) { txtChiTietGiaPhong.Text = objPHong.GiaPhong.ToString(); } } } catch { } }