<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/08/25/docking-an-applicationcontrolbar-container/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:ApplicationControlBar dock="{checkBox.selected}">
        <mx:CheckBox id="checkBox" label="dock" />
    </mx:ApplicationControlBar>

</mx:Application>