<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/17/setting-a-creation-complete-effect-on-a-button-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Style>
        Button {
            creationCompleteEffect: Zoom;
        }
    </mx:Style>

    <mx:Button id="button"
            label="Button" />

</mx:Application>