Flash Cs6 AS3 - trap ESC key to prevent exiting fullscrenn

Question

I am building a kiosk game for a trade show and want to prevent users from exiting fullscreen with ESC.

I am using Flash CS6 IDE.

I can trap the ESC key with a onKeyDown event, but I can't prevent the ESC key from exiting fullscreen on the Windows executable.

I saw a post with a solution for AIR and Flex and saw your note about stage.nativeWindow as the thing to use in Flash IDE, but I am getting a "Access of possibly undefined property nativeWindow through a reference with static type flash.display:Stage." error.

Here is the code I am using:

   function init():void
                {
                    stage.nativeWindow.addEventListener(KeyboardEvent.KEY_DOWN, escapeTrap);
                    stage.nativeWindow.displayState = StageDisplayState.FULL_SCREEN_INTERACTIVE;
                }

    function escapeTrap(event:KeyboardEvent):void
                {
                    if (event.keyCode == Keyboard.ESCAPE)
                    {
                        event.preventDefault();
                    }
                }

Thanks!