Eu tenho o código Extjs em exibição, é isso:

createPanelMC: function() {
        this.requiredSign = '<span style="color:red;font-weight:bold" data-qtip="Required">*</span>';
        var panel = Ext.create('Ext.form.Panel', {
            defaultType: 'textfield',
            name: 'nodebPanel',
            width: '100%',
            layout: {
                type: 'auto',
                align: 'stretch'
            },
            items: [{
                xtype   : 'fieldset', 
                name    : 'modlayanan',
                title   : 'Data Pelanggan',
                layout  : 'column',
                width   : '95%',
                margin  : '10',
                items: [{
                    xtype           : 'textfield',
                    name            : 'nomor',
                    id              : 'nomor',
                    fieldLabel      : 'PSTN',
                    emptyText       : 'Nomor...',
                    margin          : '10 0 0 0',
                    width           : 350,
                    labelWidth      : 100,
                    afterLabelTextTpl: this.requiredSign    
                }, {
                    xtype           : 'textfield',
                    fieldLabel      : 'Speedy',
                    name            : 'speedy',
                    id              : 'speedy',
                    margin          : '10 0 10 20',
                    width           : 350,
                    labelWidth      : 100
                },
                this.createTreePaketExist()
                ]
            }],
            dockedItems: [ {
                    xtype: 'toolbar',
                    name: 'tbpaketmc',
                    dock: 'bottom',
                    items: [ {
                            text: '<< Back',
                            action: 'doBack'
                        },'->', {
                            text: 'Submit',
                            action: 'doSubmit'
                        }
                    ]
                }
            ]
        });
        return panel;
    },

Eu chamonomor danspeedy nothis.createTreePaketExist() . Isto é othis.createTreePaketExist() código:

createTreePaketExist: function() {
        var nopstn= Ext.getCmp('nomor').getValue();
        var speedy= Ext.getCmp('speedy').getValue();
        var storeTree = Ext.create('Ext.data.TreeStore', {
            proxy: {
                type: 'ajax',
                method: 'POST',
                url: 'data/newoss_get_paket.php',
                params: { 
                        nopstn:nopstn
                        ,speedy:speedy
                }
            }
        });

    var groupProduct = Ext.create('Ext.tree.Panel', {
        store       : storeTree,
        name        : 'treeProduct',
        rootVisible : false,
        useArrows   : true,
        layout      :'fit',
        margin      : '0 0 0 0',
        autoScroll  : true,
        height      : 150,
        width       : '93%',
        listeners: 
        {
            checkchange: function(node, checked, eOpts){
                 node.eachChild(function(n) {
                node.cascadeBy(function(n){
                    n.set('checked', checked);
                });
            });
            p = node.parentNode;
            var pChildCheckedCount = 0;
            p.suspendEvents();
            p.eachChild(function(c) { 
                if (c.get('checked')) pChildCheckedCount++; 
                    p.set('checked', !!pChildCheckedCount);
                });
            p.resumeEvents();
            }
        }
    });
    return groupProduct; 
},

mas deu um erro:Ext.getCmp(...) is undefined. Ajuda-me, obrigado.