//insert du lieu vao bang cong
 public static bool insert(BangCong_Excel bc)
 {
     return(DAO_BangCong_Excel.insert(bc));
 }
 public static bool KT_TonTaiBangCong(BangCong_Excel bc)
 {
     return(DAO_BangCong_Excel.KT_TonTaiBangCong(bc));
 }