问第二个组合框在第一个更改时加载

EN

{
                           xtype : 'combo',
                           store : 'product.CategoryComboBox',
                           name: 'category',
                           displayField: 'name',
                           valueField: 'idProductCategory',
                           multiSelect : false,
                           fieldLabel: 'Category',
                           allowBlank: false,
                           allowQueryAll : false,
                           forceSelection : true,
                           typeAhead: true,
                           triggerAction: 'all',
                           delimiter : ',',
                           width: 300,
                           mode: 'local',
                           listeners:{select:{fn:function(combo, value) {
                           var attribute = Ext.getCmp('attributes');
                           var feature = Ext.getCmp('features');
                           attribute.setValue('');
                           attribute.store.removeAll();
                           attribute.setDisabled(false);
                           attribute.store.load({
                           params: {id: 5}
                         });
                           feature.setValue('');
                           feature.setDisabled(false);
                           feature.store.removeAll();
                           feature.store.load({
                           params: {id: 5}
                         });
                           //attribute.store.filter('abbr', 1);
                          }}}       
                    }