Flex ~ xml

XML
<root Label="aaaaaaaaa" Icon="Root">
<Option >
<Unit UnitID="2651" Label="xxxx">
<Sku SkuID="3490" Label="aaaaaaa" />
</Unit>
</Option>
</root>

Action Script
MainSkuID.labelField = '@Label';
MainSkuID.dataProvider = xml.Option.Unit.(@UnitID==2651).Sku;

MXML
<mx:ComboBox x="115" y="61" labelField="Label" textAlign="left" id="MainSkuID" >
</mx:ComboBox>

http://livedocs.adobe.com/flex/3/html/help.html?content=13_Working_with_XML_03.html