<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/21/detecting-when-a-radiobutton-has-been-clicked-in-a-radiobuttongroup-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white" viewSourceURL="srcview/index.html">

    <mx:Script>
        <![CDATA[
            import mx.events.ItemClickEvent;

            private function radioGroup_itemClick(evt:ItemClickEvent):void {
                var now:String = new Date().toTimeString();
                lbl.text = evt.label + " (" + now + ")";
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Label id="lbl" fontWeight="bold" />
    </mx:ApplicationControlBar>

    <mx:RadioButtonGroup id="radioGroup"
            itemClick="radioGroup_itemClick(event);" />

    <mx:VBox>
        <mx:RadioButton id="radioButton1"
                label="Red"
                group="{radioGroup}" />
        <mx:RadioButton id="radioButton2"
                label="Orange"
                group="{radioGroup}" />
        <mx:RadioButton id="radioButton3"
                label="Yellow"
                group="{radioGroup}" />
        <mx:RadioButton id="radioButton4"
                label="Green"
                group="{radioGroup}" />
        <mx:RadioButton id="radioButton5"
                label="Blue"
                group="{radioGroup}" />
    </mx:VBox>

</mx:Application>