[Flex] Hello, World!

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">
    <mx:Script>
        <![CDATA[
        import mx.controls.Alert;
            private function alert(): void {
                Alert.show("Hello, World!");
            }
        ]]>
    </mx:Script>
 <mx:Button label="Hello, World!" click="alert()" />

</mx:Application>