JSGrid Dependent Filters

HTML

<link rel="stylesheet" href="http://js-grid.com/css/jsgrid.min.css">
<link rel="stylesheet" href="http://js-grid.com/css/jsgrid-theme.min.css">
<script src="http://js-grid.com/js/jsgrid.min.js"></script>
<script src="http://underscorejs.org/underscore-min.js"></script>
<link rel="stylesheet" href="https://code.jquery.com/ui/1.10.4/themes/redmond/jquery-ui.css">
<script src="https://code.jquery.com/ui/1.11.2/jquery-ui.js"></script>
<div id="jsGrid"></div>

JavaScript

var db = {

        loadData: function(filter) {
            return $.grep(this.clients, function(client) {
                return (!filter.Country || client.Country === filter.Country)
                    && (!filter.State || client.State === filter.State);
            });
        }

    };

    window.db = db;

db.countries = [
    { Name: "", Id: 0, States: [] },
    { Name: "United States", Id: 1, States: [1, 2] },
    { Name: "Canada", Id: 2, States: [3, 4] },
    { Name: "Australia", Id: 3, States: [5, 6] },
    { Name: "New Zealand", Id: 4, States: [7, 8] },
    { Name: "UK", Id: 5, States: [9, 10] }
     
];

db.states = [
    { Id: 0, Name: "" },
    { Id: 1, Name: "A1" }, 
    { Id: 2, Name: "B1" },
    { Id: 3, Name: "A2" },
    { Id: 4, Name: "B2" },
    { Id: 5, Name: "A3" },
    { Id: 6, Name: "B3" },
    { Id: 7, Name: "A4" },
    { Id: 8, Name: "B4" },
    { Id: 9, Name: "A5" },
    { Id: 10, Name: "B5" }
];

db.clients = [
    {
        "Name": "Otto Clay",
        "Country": 1,
        "State": 1
    },
    {
        "Name": "Connor Johnston",
        "Country": 1,
        "State": 2
    },
    {
        "Name": "Lacey Hess",
        "Country": 2,
        "State": 3
    },
    {
        "Name": "Timothy Henson",
        "Country": 2,
        "State": 4
    }
];

$("#jsGrid").jsGrid({
        width: "100%",
        autosize: true,
        inserting: true,
        editing: true,
        sorting: true,
        paging: true,
        confirmDeleting: true,
        deleteConfirm: "Are you sure you want to delete this item?",
 
        controller: db,
    
        fields: [
            { 
                name: "Name", 
                type: "textarea", 
                width: 150 
            }, { 
                name: "Country", 
                type: "select", 
                items: db.countries,
                valueField: "Id",
                textField: "Name",
                   itemTemplate: function (countryId) {
                       ...