public bool ThemPhiThang(ref string err, int Thang1, int Nam1, string LoaiPhi, decimal Gia) { bool f = false; try { dbs.SP_ThemPhiThang(Thang1, Nam1, LoaiPhi, Gia); dbs.SubmitChanges(); f = true; } catch (Exception ex) { err = ex.Message; } return(f); }