ATMLCommonLibrary.controls.IndentificationNumbersListControl.IndentificationNumbersListControl_OnAdd C# (CSharp) Method

        private void IndentificationNumbersListControl_OnAdd()
        {
            var form = new IdentificationNumberForm();
            form.IdentificationNumber = new IdentificationNumber();
            if (DialogResult.OK == form.ShowDialog())
            {
                IdentificationNumber id = form.IdentificationNumber;
                String idType = "";
                if (id is ManufacturerIdentificationNumber)
                    idType = "MFR";
                else if (id is UserDefinedIdentificationNumber)
                    idType = "USR";

                var lvi = new ListViewItem(idType);
                lvi.SubItems.Add(id.number);
                lvi.SubItems.Add(id.type.ToString());
                lvi.SubItems.Add(id is UserDefinedIdentificationNumber
                    ? ((UserDefinedIdentificationNumber) id).qualifier
                    : "");
                if (id is ManufacturerIdentificationNumber)
                    lvi.SubItems.Add(((ManufacturerIdentificationNumber)id).manufacturerName);
                else
                    lvi.SubItems.Add("");
                lvi.Tag = id;
                Items.Add(lvi);
                if (_identificationNumbers == null)
                    _identificationNumbers = new List<IdentificationNumber>();
                _identificationNumbers.Add(id);
                lvi.BackColor = lvi.Index % 2 == 0 ? ATMLContext.COLOR_LIST_EVEN : ATMLContext.COLOR_LIST_ODD;
            }
        }