protected virtual void Contact_BAccountID_FieldVerifying(PXCache sender, PXFieldVerifyingEventArgs e) { Contact contact = (Contact)e.Row; if (contact.BAccountID != (int?)e.NewValue && contact.ContactID > 0) { CRCase crCase = Cases.SelectSingle(); CROpportunity op = Opportunities.SelectSingle(); if (crCase != null || op != null) { throw new PXSetPropertyException(Messages.CannotChangeBAccount); } } }