package
{
    import mx.core.Application;
    import mx.controls.Button;
    import flash.events.MouseEvent;


    public class CustomApp extends Application
    {
        public var mutton:Button;

        function CustomApp()
        {
            mutton.addEventListener(MouseEvent.CLICK, butterCup);
        }

        public function butterCup(event:MouseEvent):void
        {
            trace("clicked " + event);
        }

    }
}