private void detach_SaleInvoices(SaleInvoice entity)
 {
     this.SendPropertyChanging("SaleInvoices");
     entity.ItemInstance = null;
 }
 private void detach_SaleInvoices(SaleInvoice entity)
 {
     this.SendPropertyChanging("SaleInvoices");
     entity.SaleSellitem = null;
 }