Extjs 3.0 multiselect根据选择的哪项右边的iframe显示数据解决办法

Extjs 3.0 multiselect根据选择的哪项右边的iframe显示数据
效果就像asp.net ListBox 把autoAutoPostBack 设置为"true" 
请问在Extjs multiselect的事件中该如何写 望高手给予指点
下面是我写的但是在我选择multiselect中的items时 listeners事件不被触发

JScript code

{        xtype: 'multiselect',        name: 'multiselect',        store: Store,        width: 200,        AutoHeight: true,        allowBlank:false,        valueField:"value",        displayField:"text",        listeners:{                  select:function(multiselect, record,index){         var selectionsArray = this.multiselect.view.getSelectedIndexes();        var records = [];        if (selectionsArray.length > 0) {            for (var i=0; i<selectionsArray.length; i++) {                        record = this.multiselect.view.store.getAt(selectionsArray[i]);                        records.push(record);                    }                }        Ext.MessageBox.alert("恭喜",records);        }}

JScript code

多选框这样来配置，如果要重写或添加方法可以看看扩展api{                                xtype: "itemselector", name: "", fieldLabel: "查看", msWidth: 170, msHeight: 150, valueField: "id", displayField: "text",                                imagePath: "JavaScript/MultiSelect/", fromLegend: "可选", toLegend: "已选", fromStore: StoresFrom, toStore: StoresTo                            },