구조 extjs 2단계 연동comBox

 {
                columnWidth: .25,
                layout: "form",
                items: [{
                    xtype: 'combo',
                    fieldLabel: " ",
                    editable: false,
                    //  

                       hiddenName: 'quyu',
                    store: areaStore,
                    mode: 'remote',// combo remote
                    triggerAction: 'all',
                    emptyText: ' ',
                    width: 100,
                    displayField: 'param_value',
                    allowBlank: false,
                    blankText: " ",
                    listeners: {

                        select: function (combo) {

                            var quyu = form.getForm().findField("quyu").getValue();
                            form.getForm().findField("Name").clearValue(); // ， combo   

                            ProjectStore.load({ params: { quyu: quyu} });// combo 

                        }

                    }
                }]
            },
            {
                columnWidth: .25,
                layout: "form",
                items: [{
                    xtype: 'combo',
                    fieldLabel: " ",
                    editable: false,
                    //  

                       hiddenName: 'Name',
                    store: ProjectStore,// 
                    mode: 'local',// combo local
                    triggerAction: 'all',
                    emptyText: ' ',
                    width: 100,
                    displayField: 'name',
                    allowBlank: false,
                    blankText: " "
                }]
            }