<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/10/01/data-binding-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        creationComplete="init();">

    <mx:Script>
        <![CDATA[
            import mx.binding.utils.BindingUtils;

            private function init():void {
                BindingUtils.bindProperty(textInputDst, "text", textInputSrc, "text");
            }
        ]]>
    </mx:Script>

    <mx:Form>
        <mx:FormItem label="source:">
            <mx:TextInput id="textInputSrc" />
        </mx:FormItem>
        <mx:FormItem label="destination:">
            <mx:TextInput id="textInputDst"
                    width="{textInputSrc.width}" />
        </mx:FormItem>
    </mx:Form>

</mx:Application>