MVVM editing

HTML

<script src="http://cdn.kendostatic.com/2012.1.229/js/kendo.all.min.js"></script>
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.229/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.1.229/styles/kendo.default.min.css">
<div id="MainWindow">
    <div >Main Window</span></div>
    <span data-bind="text: ProductName"></span>
    <button data-bind="click: ShowUpdateWindow">Update Window</button>
</div>

<div id="UpdateWindow">
    <div>Update Window</span></div>
    <input data-bind="value: ProductId" />
    <button data-bind="click: CancelUpdateWindow">Back</button>
    <button data-bind="click: UpdateId">Update Id</button>
</div>

JavaScript

dataSource = new kendo.data.DataSource({
        schema: {
            model: { id: "Id" }
        },
        transport: {
            read: {
                dataType: "jsonp",
                url: "http://demos.kendoui.com/service/Products"
            },
            update: {
                url: "http://demos.kendoui.com/service/Products/Update",
                dataType: "jsonp"
            },
            parameterMap: function(options, operation) {
                if (operation !== "read" && options.models) {
                    return {
                        models: kendo.stringify(options.models)
                    };
                }
            }
        },
        change: function () {
            viewModel.data = dataSource.view()[0];
            kendo.bind($("#MainWindow, #UpdateWindow"), viewModel);
        }
    });

    var viewModel = new kendo.data.ObservableObject({
        data: [],
        ProductName: function () { return this.get("data.ProductName"); },
        ProductId: function () { return this.get("data.ProductID"); },
        ShowUpdateWindow: function () {
            alert("Showing update window");
            $("#MainWindow").slideUp(300);
            $("#UpdateWindow").slideDown(300);
        },
        CancelUpdateWindow: function () {
            alert("Showing cancel window");
            $("#UpdateWindow").slideUp(300);
            $("#MainWindow").slideDown(300);
        },
        UpdateId: function () {
            alert("Updating");
            dataSource.sync();
        }
    });

    $("#UpdateWindow").hide();
    dataSource.read();