Data Grid XML filtering

Question

I cant sem to figure out how to filter my XML data before entering my data grid. I want to load only the XML data with the ID attribute "BALUSTER" and have tried entering:
data_grid.dataProvider = dp.(@ID == "BALUSTER");
into my xmlLoaded function without any success.  I am fairly new to as3 and could definitely use the help.  Thanks.
var dpataProvider;
var products_xml:XML;
var xmlReq:URLRequest = new URLRequest("data/products.xml");
var xml_loader:URLLoader = new URLLoader();
function xmlLoaded(event:Event):void {
var ldr:URLLoader = event.currentTarget as URLLoader;
var xmlDP:XML = new XML(ldr.data);
dp = new DataProvider(xmlDP);
data_grid.dataProvider = dp;
xml_loader.load(xmlReq);
xml_loader.addEventListener(Event.COMPLETE, xmlLoaded);

Answer 1

Hard to say without seeing your xml, but something along these lines might work for you:
import fl.data.DataProvider;
var rawXml:XML =
<xml>
<item ID="BALUSTER">
  <moniker>bubba</moniker>
  <age>50</age>
</item>
<item ID="BALUSTER">
  <moniker>bobby-sue</moniker>
  <age>13</age>
</item>
<item ID="BULLUSTER">
  <moniker>boo</moniker>
  <age>25</age>
</item>
</xml>;
// use a second XML object to hold the selected nodes
var data:XML = <data/>;
data.setChildren(rawXml.item.(@ID == "BALUSTER"));
var dp:DataProvider = new DataProvider(data);
data_grid.dataProvider = dp;