flex datagrid 多个单选按钮

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="init()" layout="absolute" xmlns:ns1="com.component.*">
<mx:Script>
 <![CDATA[
  import com.component.DataHBox;
  import com.component.GridDataObject;
  import mx.collections.ArrayCollection;
  import mx.controls.dataGridClasses.DataGridColumn;
  import mx.controls.Alert;
  [Bindable]
   var xml:XML=
   <root><data name='德阳市卫生执法监督所' pid='10777 ' czjb='2' flag="2"/>
   <data name='泰山社区卫生服务中心' pid='10795 ' czjb='3'  flag="3"/>
   <data name='八角镇卫生院' pid='10783 ' czjb='2' flag="2"/>
   <data name='德阳市第二人民医院' pid='10770 ' czjb='3' flag="3"/>
   <data name='扬嘉镇卫生院' pid='10794 ' czjb='2'  flag="2"/>
  
   </root>;
        [Bindable]
        var arry:ArrayCollection=new ArrayCollection;
        function test(evt:Event):void{
         var s:DataHBox=DataHBox(evt.currentTarget);
         Alert.show(grid.selectedItem.@name+":"+":"+grid.selectedItem.@index+":"+s.itemValue)
      
        }
        function init():void{
         var length:int=xml.data.length();
         var a:Array=[];
         for(var i:int=0;i<length;i++){
         var s:GridDataObject=new GridDataObject;
         s.name=xml.data[i]