If anyone can help here's what I'm trying to do, I have a grid, with data from my store, if an item is double clicked then a controller handles the event and opens up an edit window, the form loads from the passed in record. So the form has a record defined, the way I understand updateRecord() is that it does not require a record parameter if the form already has one associated to it.

But I am getting the following error. (Uncaught TypeError: Cannot read property 'fields' of undefined)


Here is the controller

Code:
Ext.define('Inters.controller.IntersController', {    extend: 'Ext.app.Controller',


    views: [
        'Inters'
    ],


    onGridviewItemDblClick: function(tablepanel, record, item, index, e, options) {
        // console.log(record.get('studentid'));


        var x = Ext.create('Inters.view.Edit');


        Ext.getCmp('Overview').loadRecord(record);


        x.show();
    },


    init: function(application) {
        this.control({
            "gridpanel": {
                itemdblclick: this.onGridviewItemDblClick
            }
        });
    }


});


And the Edit window definition with the btnSave click event that I am getting the error.
Code:
Ext.define('Inters.view.Edit', {    extend: 'Ext.window.Window',


    height: 502,
    id: 'wEdit',
    width: 752,
    title: 'Edit',
    modal: true,


    initComponent: function() {
        var me = this;


        Ext.applyIf(me, {
            dockedItems: [
                {
                    xtype: 'tabpanel',
                    dock: 'top',
                    height: 472,
                    activeTab: 0,
                    dockedItems: [
                        {
                            xtype: 'form',
                            dock: 'top',
                            height: 427,
                            id: 'Overview',
                            layout: {
                                type: 'absolute'
                            },
                            bodyPadding: 10,
                            title: 'Overview',
                            items: [
                                {
                                    xtype: 'textfield',
                                    id: 'frmFirstName',
                                    width: 260,
                                    name: 'firstname',
                                    fieldLabel: 'First name'
                                },
                                {
                                    xtype: 'textfield',
                                    x: 10,
                                    y: 50,
                                    id: 'frmLastName',
                                    width: 260,
                                    name: 'lastname',
                                    fieldLabel: 'Last name'
                                },
                                {
                                    xtype: 'button',
                                    x: 297,
                                    y: 255,
                                    id: 'btnSave',
                                    text: 'Save',
                                    listeners: {
                                        click: {
                                            fn: me.onBtnSaveClick,
                                            scope: me
                                        }
                                    }
                                }
                            ]
                        }
                    ]
                }
            ]
        });


        me.callParent(arguments);
    },


    onBtnSaveClick: function(button, e, options) {


        console.info(button);
        console.log(e);
        console.log(options);


        var basicForm = button.up('form').getForm();
        basicForm.updateRecord(basicForm.record);
    }


});

Does anyone have any suggestions, answers to my problem. I am new to ExtJS and an intermediate js programmer with little experience with frameworks.