Flex 创建有滚动条Panel

<?xml version="1.0" encoding="utf-8"?>
<s:Module xmlns:fx="http://ns.adobe.com/mxml/2009"
    xmlns:s="library://ns.adobe.com/flex/spark"
    xmlns:mx="library://ns.adobe.com/flex/mx"
    minWidth="605"
    alpha="1.0"
    percentHeight="100"
    initialize="Init(event)">
 <fx:Script>
  <![CDATA[
   import Template.ItemList;

   import mx.collections.ArrayCollection;
   import mx.events.FlexEvent;
   import mx.rpc.events.ResultEvent;
   import mx.controls.Alert;
   import org.Hw.entity.VehicleDynamicView;

   [Bindable]
   private var v:VehicleDynamicView=new VehicleDynamicView();

   [Bindable]
   private var vDynamic:ItemList=new ItemList();

   [Bindable]
   private var arr:ArrayCollection=new ArrayCollection();

   protected function Init(event:FlexEvent):void
   {
    dymic.getList("");
   }

   protected function getListHandler(event:ResultEvent):void
   {
    var arr:ArrayCollection=event.result as ArrayCollection;
    for (var i:Number=0; i < arr.length; i++)
    {
     var vd:VehicleDynamicView=new VehicleDynamicView();
     var vDynamic:ItemList=new ItemList();
     v=arr[i];
     vd=arr[i];
     vDynamic.v=vd;
     vDynamic.y=38 * i;
     //myp.addElement(vDynamic);
     myGroup.addElement(vDynamic);
    }

   }
  ]]>
 </fx:Script>
 <fx:Declarations>
  <!-- 将非可视元素（例如服务、值对象）放在此处 -->
  <s:RemoteObject id="dymic"
      destination="Vdynamic">
   <s:method name="getList"
       result="getListHandler(event)"/>
  </s:RemoteObject>
 </fx:Declarations>
 <s:Panel id="myp"
    left="10"
    right="20"
    top="15"
    bottom="15"
    fontSize="16"
    percentHeight="100"
    backgroundAlpha="0.5"
    contentBackgroundAlpha="0.5"
    skinClass="Template.SysPanelSkinClass"
    horizontalCenter="0"
    title="{v.groupname} 车辆总数({v.allcount})">
  <s:Scroller width="100%"
     height="100%">
   <s:Group width="100%"
      height="100%">
    <s:VGroup left="0"
        right="0"
        top="0"
        bottom="0"
        id="myGroup">

    </s:VGroup>

   </s:Group>

  </s:Scroller>

 </s:Panel>
</s:Module>