public static void delModelReturn(string performanceId,DateTime? effectiveDate=null)

        {

            using (SqlConnection con = GetEditorConnection())

            {

                con.Open();

                using (SqlCommand command = con.CreateCommand())

                {

                    SqlTransaction st = con.BeginTransaction();

                    command.Transaction = st;

                    try

                    {

                        command.CommandText = "delModelReturn";

                        command.CommandType = CommandType.StoredProcedure;

                        command.Parameters.Add(new SqlParameter("@p_PerformanceId", performanceId));

                        if (!effectiveDate.HasValue)

                        {

                            command.Parameters.Add(new SqlParameter("@p_EffectiveDate", DBNull.Value));

                        }

                        else

                        {

                            command.Parameters.Add(new SqlParameter("@p_EffectiveDate",effectiveDate));

                        }

                        command.ExecuteNonQuery();

                        st.Commit();

                    }

                    catch (Exception ex)

                    {

                        st.Rollback();

                        throw new Exception(ex.Message);

                    }

                }

                con.Close();

            }

        }