private void btnDuyet_Click(object sender, EventArgs e)
{
int loaiPhong = int.Parse(cmbLoaiPhong.SelectedValue.ToString());
int tinhTrang = int.Parse(cmbTinhTrang.SelectedValue.ToString());
HienThiDanhSachPhong(PhongDAO.DuyetDSPhong(loaiPhong, tinhTrang));
}