as3 unhandled error catching

gistfile1.as

loaderInfo.uncaughtErrorEvents.addEventListener(UncaughtErrorEvent.UNCAUGHT_ERROR, function( evt : UncaughtErrorEvent ):void{
	evt.preventDefault();
        
        var message:String;
             
        if (event.error is Error) message = Error(event.error).message;
        else if (event.error is ErrorEvent) message = ErrorEvent(event.error).text;
        else message = event.error.toString();

        trace("Uncaught error: "+message); 
});