Saving handsontable data

app.js

(function ($) {
    if ($) {
        var hst = (function () {
            var $container = $("#hst");

            $container.handsontable({
                startRows: 8,
                startCols: 6,
                rowHeaders: true,
                colHeaders: true,
                minSpareRows: 1,
                contextMenu: true
            });

            hst = $container.data('handsontable');

            var $dataLocker = $("#dataLocker").val();

            if ($dataLocker.length > 0) {
                var data = JSON.parse($dataLocker);

                hst.loadData(data);
            }
            return hst;
        })();

        // Enable a click handler for the button to save data and submit the form
        $("#saveContent").click(function (e) {
            // Save the table data before sending the form
            $("#dataLocker").val(JSON.stringify(hst.getData()));
            $("body > form").submit();
        });
    }
})(jQuery);

index.aspx.cs

using System;
using System.Collections.Generic;
using System.Web.UI.HtmlControls;
using Newtonsoft.Json;

namespace HandsonDemo
{
    public partial class _Default : System.Web.UI.Page
    {
        protected HtmlInputHidden dataLocker;
        private List<List<int?>> Data = new List<List<int?>>
        {
            new List<int?> { 1, 2, 3, 4, 5, 6 },
            new List<int?> { 7, 8, 9, 10, 11, 12 },
            new List<int?> { 13, 14, 15, 16, 17, 18 },
            new List<int?> { 19, 20, 21, 22, 23, 24 },
        };

        protected void Page_Load(object sender, EventArgs e)
        {
            if (IsPostBack)
            {
                // if we are posting data to the server deserialize it so that we can manipulate it
                Data = JsonConvert.DeserializeObject<List<List<int?>>>(dataLocker.Value);
            }

            // store the data object to be rendered to the handsontable
            dataLocker.Value = JsonConvert.SerializeObject(Data);
        }
    }
}