Flex中删除Tree的节点

//删除菜单节点   
    private function deleteMenuItem(event:Event):void  
    {   
     var xml:XML = _mainPortal.myTree.selectedItem as XML;   
        
      if( xml == null ) return;   
      //删除菜单节点的子节点   
      deleteChildren(xml);   
    
      if(xml.parent().hasOwnProperty("node") == true)   
      {   
       var parentxml:XML=xml.parent() as XML;   
         for(var i:uint;i<parentxml.child("node").length();i++)   
         {   
         if(parentxml.child("node")[i]==xml[0])   
    {   
     delete parentxml.children()[i];   
    }   
         }    
      }   
      else  
      {   
       Alert.show("新添加的节点才能删除！","系统提示");   
      }   
    }   
  
//删除子节点   
    private function deleteChildren(parentxml:XML):void  
    {   
     var xml:XML = parentxml;   
        
      if( xml == null ) return;   
      if(xml.hasOwnProperty("node") == true)   
      {   
       for(var i:uint=0; i<xml.child("node").length();i++)   
       {   
         delete xml.children()[i];   
       }    
      }         
    }   
  



<mx:Button label="删除" click="deleteMenuItem(event)"/>