<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/25/detecting-when-a-radiobuttongroup-has-been-enabled-or-disabled-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        initialize="init();">

    <mx:Script>
        <![CDATA[
            import mx.containers.ApplicationControlBar;
            import mx.containers.Form;
            import mx.containers.FormItem;
            import mx.containers.HBox;
            import mx.controls.Alert;
            import mx.controls.CheckBox;
            import mx.controls.RadioButton;
            import mx.controls.RadioButtonGroup;

            private var checkBox:CheckBox;
            private var radioGroup:RadioButtonGroup;
            private var radioButton1:RadioButton;
            private var radioButton2:RadioButton;
            private var radioButton3:RadioButton;
            private var radioButton4:RadioButton;
            private var radioButton5:RadioButton;

            private function init():void {
                checkBox = new CheckBox();
                checkBox.selected = true;
                checkBox.addEventListener(Event.CHANGE, checkBox_change);

                var formItem:FormItem = new FormItem();
                formItem.label = "enabled:";
                formItem.addChild(checkBox);

                var form:Form = new Form();
                form.styleName = "plain";
                form.addChild(formItem);

                var appControlBar:ApplicationControlBar = new ApplicationControlBar();
                appControlBar.dock = true;
                appControlBar.addChild(form);
                Application.application.addChildAt(appControlBar, 0);

                radioGroup = new RadioButtonGroup();
                radioGroup.addEventListener("enabledChanged", radioGroup_enabledChanged);

                radioButton1 = new RadioButton();
                radioButton1.label = "Red";
                radioButton1.group = radioGroup;

                radioButton2 = new RadioButton();
                radioButton2.label = "Orange";
                radioButton2.group = radioGroup;

                radioButton3 = new RadioButton();
                radioButton3.label = "Yellow";
                radioButton3.group = radioGroup; 

                radioButton4 = new RadioButton();
                radioButton4.label = "Green";
                radioButton4.group = radioGroup;

                radioButton5 = new RadioButton();
                radioButton5.label = "Blue";
                radioButton5.group = radioGroup;

                var hBox:HBox = new HBox();
                hBox.setStyle("horizontalGap", 54);
                hBox.addChild(radioButton1);
                hBox.addChild(radioButton2);
                hBox.addChild(radioButton3);
                hBox.addChild(radioButton4);
                hBox.addChild(radioButton5);
                addChild(hBox);
            }

            private function radioGroup_enabledChanged(evt:Event):void {
                Alert.show("RadioButtonGroup enabled was changed",
                            "enabled: " + radioGroup.enabled);
            }

            private function checkBox_change(evt:Event):void {
                radioGroup.enabled = !radioGroup.enabled;
            }
        ]]>
    </mx:Script>

</mx:Application>