private void txtIDPhong_TextChanged(object sender, EventArgs e) { PhongDTO phongDTO = PhongBUS.GetPhongDTO(txtIDPhong.Text); if (phongDTO == null) { lblKhuNha.Text = ""; lblSoPhong.Text = ""; } else { lblKhuNha.Text = phongDTO.KhuNha; lblSoPhong.Text = phongDTO.SoPhong; } if (CheDoHienTai == CheDo.THEM) { if (!PhongBUS.KiemTraPhong(txtIDPhong.Text)) { lblNotSuitableRoom.Show(); } else { lblNotSuitableRoom.Hide(); } } else { lblNotSuitableRoom.Hide(); } }