I have Extjs ViewPort panel, that contain center panel, that contain tablpanel, in which I have added gridpanel in one tab, on this I have put 'Add Person' button in tbar of , that will add a new tab of a FormPanel, in its Reset button, I am not able to access Form to reset it.

Do any body have faced same issue... please help how to get it working.

Ext.onReady(
    function(){
        // Ext.get(document.body, true).toggleClass('xtheme-gray');

        var myBorderPanel
            = new Ext.Viewport({
                title: 'Software Releases',
                // renderTo: document.body,

                renderTo: Ext.getBody(),
                layout: 'border',
                id: 'main',
                items: [
                    {
                        title:  'Center Region',
                        region: 'center',     // center region is required, no width/height specified
                        tbar: [
                            {
                                text: 'Add person', // only when user have write priovilege.
                                handler: function() {
                                    var tabpanel = Ext.getCmp('main').findById('tabs');

                                    var wtab = tabpanel.add({
                                        //     // var addrelease_win = new Ext.Window({
                                        url:    'reledit-submit.json',
                                        id:     'addform0',
                                        // height: 300, width: 400,
                                        layout: 'form',
                                        frame: true,
                                        title: 'Add New Release',
                                        closable: true,

                                        items: [
                                            { xtype: 'textfield', fieldLabel: 'Name' }


                                        buttons: [{
                                            text: 'Save',
                                            scope: wtab,
                                            handler: function() {
                                                wtab.getForm().submit({
                                                    success: function(f,a) {
                                                        Ext.Msg.alert('Success', 'It worked');
                                                    },
                                                    failure: function(f,a){
                                                        Ext.msg.alert('Warnning', 'Error');
                                                    }
                                                });
                                            }
                                        },{
                                            text: 'Reset',
                                            scope: wtab,
                                            handler: function() {
                                                // Ext.getCmp('addform0').getForm().reset();
                                                // tabpanel.getActiveTab.reset();
                                                // Ext.getCmp('main').findById('addform').getForm().reset();
                                                // this.getForm().reset();
                                                // this.getForm().reset();
                                                // Ext.Msg.alert('sdfsd', 'asdfsd ' + Ext.getCmp('addform0').getValue() + ' sdfsd');
                                                this.findById('addform0').getForm().reset();
                                                // Ext.Msg.alert('sdfsd', 'asdfsd ');
                                            }
                                        }]

                                    });
                                    // addrelease_win.show();

                                    tabpanel.activate(tabpanel.items.length - 1);
                                }
                            }
                        ],
                        xtype:  'tabpanel',
                        id:     'tabs',
                        activeTab: 0,
                        items: [{
                            title: 'Data',
                            xtype: 'editorgrid',
                            store:  store,
                            stripeRows: true,
                            // autoExpandColumn: 'title',
                            columns: [
                                {header:   "Name"         ,  dataIndex: "name"     , width: 50, sortable: true},
                                {header:   "DOB",  dataIndex: "dob" , sortable: true}
                            ],
                            })
                        }],
                        margins: '5 5 0 0'
                    }
              ]
            });

    }