addTheAddOnItemToCart: function regProdModelAddToCart(itemIds) {
  var url = '/api/items?id=' + itemIds.join(',') + '&fieldset=details&currency=USD';
  var liveOrderModel = LiveOrderModel.getInstance();

  jQuery.ajax({
    type: 'get',
    url: url,
    data: '',
    contentType: 'application/json',
    dataType: 'jsonp',
    jsonpCallback: 'fnCallback',
    success: function (results) {
      var lines = [];

      results.items.forEach(function (item) {
        var item = new ItemModel(item);
        var product = new ProductModel({
          quantity: 1,
          item: item,
          _optionsDetails: [],
          options: []
        });

        product.setOption('custcol_serial_reference2', 'hi mom'); // Testing...

        lines.push(LiveOrderLineModel.createFromProduct(product));
      });

      var cart_promise = liveOrderModel.addLines(lines);
      CartConfirmationHelpers.showCartConfirmationMultiple(cart_promise, lines, SC._applications.MyAccount);

    },
    error: function (jqXHR, textStatus, errorThrown) {
      console.error('RegisteredProductsView: ' + textStatus + ' ... ' + errorThrown);
    },
    complete: function () {
      /* nothing for now */
    }
  });
},