<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/02/26/displaying-a-tree-control-as-a-pop-up-for-a-flex-popupbutton-control/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Style>
    	Tree {
    		textAlign: left;
    		fontWeight: normal;
    	}
    </mx:Style>

    <mx:XML id="mlb" source="mlb.xml" />

    <mx:ApplicationControlBar dock="true">
		<mx:PopUpButton label="Please select a team...">
			<mx:popUp>
			    <mx:Tree id="tree"
			            dataProvider="{mlb}"
			            labelField="@label"
			            showRoot="false"
			            width="200"
			            rowCount="8" />
			</mx:popUp>
		</mx:PopUpButton>
    </mx:ApplicationControlBar>

</mx:Application>