private bool check_nv_da_co_hop_dong(string ma_nv)
{
//decimal id_nv = find_id_nv_by_ma_nv(ma_nv);
//decimal id = (from DataRow dr in m_dt_ma_hop_dong.Rows
// where (decimal)dr["ID_NHAN_VIEN"] == id_nv
// select (decimal)dr["ID"]).FirstOrDefault();
//if (id > 0)
//{
// return true;
//}
//else
//{
// return false;
//}
return false;
}