flex&webservice

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="wsBlogAggr.getMostPopularPosts.send()">
 <mx:WebService id="wsBlogAggr" wsdl="http:weblogs.macromedia.com/mxna/webservices/mxna2.cfc?wsdl" useProxy="false">
  <mx:operation name="getMostPopularPosts">
   <mx:request xmlns="">
    <daysBack>
     30
    </daysBack>
    <limit>
     {cbxNumPosts.value}
    </limit>
   </mx:request>
   
  </mx:operation>
 </mx:WebService>
 <mx:Panel x="10" y="10" width="475" height="400" layout="absolute" title="Most Popular Posts">
  <mx:ComboBox x="30" y="25" id="cbxNumPosts" change="wsBlogAggr.getMostPopularPosts.send()">
   <mx:Object  label="top 5" data="5"/>
   <mx:Object label="top 10" data="10"/>
   <mx:Object label="top 15" data="15"/>
   </mx:ComboBox>
   <mx:DataGrid x="30" y="75" id="dgTopPosts" width="400" dataProvider="{wsBlogAggr.getMostPopularPosts.lastResult}">
    <mx:columns>
     <mx:DataGridColumn  headerText="Top Posts" dataField="postTitle"/>
     <mx:DataGridColumn headerText="Clicks" dataField="clicks" width="75"/>
    </mx:columns>
    
   </mx:DataGrid>
    <mx:LinkButton x="30" y="250" label="Select an item and click here for full post"/>
    
  
 </mx:Panel>
 
</mx:Application>