I want to populate an external xml file into an advancedDataGrid using
HttpService. But I simply cannot get it to work. Here are my codes. Can someone
take a look and find out what's wrong with my codes?

---data.xml---
<?xml version="1.0"?>
<Region Region="Southwest">
<Region Region="Arizona">
<Territory_Rep Territory_Rep="Barbara Jennings"
Actual="38865" Estimate="40000"/>
<Territory_Rep Territory_Rep="Dana Binn"
Actual="29885" Estimate="30000"/>
</Region>
<Region Region="Central California">
<Territory_Rep Territory_Rep="Joe Smith"
Actual="29134" Estimate="30000"/>
</Region>
<Region Region="Nevada">
<Territory_Rep Territory_Rep="Bethany Pittman"
Actual="52888" Estimate="45000"/>
</Region>
<Region Region="Northern California">
<Territory_Rep Territory_Rep="Lauren Ipsum"
Actual="38805" Estimate="40000"/>
<Territory_Rep Territory_Rep="T.R. Smith"
Actual="55498" Estimate="40000"/>
</Region>
<Region Region="Southern California">
<Territory_Rep Territory_Rep="Alice Treu"
Actual="44985" Estimate="45000"/>
<Territory_Rep Territory_Rep="Jane Grove"
Actual="44913" Estimate="45000"/>
</Region>
</Region>

---mxml---
<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
creationComplete="init()">

<mx:Script>
<![CDATA[
import mx.collections.HierarchicalData;
import mx.collections.XMLListCollection;
import mx.rpc.events.ResultEvent;
import mx.rpc.http.HTTPService;


[Bindable]
private var _Data:XMLListCollection;

private var myHttp:HTTPService;

private function init():void{
myHttp = new HTTPService();
myHttp.url = "data.xml";
myHttp.resultFormat = "e4x";
myHttp.send();
myHttp.addEventListener(ResultEvent.RESULT, resultHandler);
}

private function resultHandler(event:ResultEvent):void{
_Data = new XMLListCollection(event.result.Region);
}
]]>
</mx:Script>

<mx:AdvancedDataGrid width="100%" height="100%" >
<mx:dataProvider>
<mx:HierarchicalData source="{_Data}"/>
</mx:dataProvider>
<mx:columns>
<mx:AdvancedDataGridColumn dataField="@Region"
headerText="Region"/>
<mx:AdvancedDataGridColumn dataField="@Territory_Rep"
headerText="Territory Rep"/>
<mx:AdvancedDataGridColumn dataField="@Actual"
headerText="Actual"/>
<mx:AdvancedDataGridColumn dataField="@Estimate"
headerText="Estimate"/>
</mx:columns>
</mx:AdvancedDataGrid>
</mx:Application>