I am a newbie at Ext.Js and I am currently trying to integrate it with ASP.NET MVC 3. Although, I've been able to get Ext.Js using its own MVC framework going, I'm having trouble integrating it within ASP.NET MVC 3.

Effectively, I'm trying to insert a GridPanel into my ASP.NET MVC file i.e. I'm not using an Ext.Js container but I'll manage the container myself. I've tried following the examples here http://docs.sencha.com/ext-js/4-0/#/api/Ext.grid.Panel and http://www.sencha.com/learn/the-grid-component/ but I get errors within ext-debug.js

In any case after some trial and error, this is the code that I've come up with:

Code:
<asp:Content ID="InventoryPartList" ContentPlaceHolderID="MiddleColumn" runat="server">
  
    <div id="senchaGrid"></div>
    <script type="text/javascript">
    Ext.onReady(function () {

                var myModel = Ext.define('InventoryPart', {
                    extend: 'Ext.data.Model',
                    fields: ['partNum', 'description']
                });

               var myStore = Ext.define('InventoryParts', {
                    extend: 'Ext.data.Store',
                    model: myModel,
                    autoLoad: true,
                               

                    proxy: {
                        type: 'ajax',
                        api: {
                            read: 'http://david-7/Inventory/InventoryPart/InventoryPartListSencha'
                            //            ,update: 'data/updateUsers.json'
                        },
                        reader: {
                            type: 'json',
                            root: 'inventoryparts',
                            successProperty: 'success'
                        }
                    }
                });

                Ext.create('Ext.grid.Panel', {
                    renderTo: 'senchaGrid',
                    store: myStore,
                    width: 400,
                    height: 200,
                    title: 'Application Users',
                    columns : [
                    { header: 'Part Number', dataIndex: 'partNum', flex: 1 },
                    { header: 'Description', dataIndex: 'description', flex: 1 }
                ]
                });

    });




    </script>
    
</asp:Content>
However, I get the following error:

me.model is undefined
this.readyListeners.push({ ext-debug.js (line 7696)

At this point I don't quite know what I'm doing wrong and how to resolve it. Can anyone spot what I'm not doing quite right?