Action Script. How to disable keyboard? - actionscript-3

Question

how to disable keyboard keys in Action Script?
I'm creating Flash "memory" game, Idea to discover 2 equal cards. When 2nd card is discovered it is shown for 750 milliseconds, in that time player can't do any actions.
When I use this mouseChildren = false; player can't click with mouse for this time, but he can use keyboard arrows/enter/space/tab buttons... I need to disable It for this time.
Here is part of my code:
{
trace("Wrong");
_message = "Wrong";
message_txt.text = _message;
_secondCard = event.currentTarget;
var timer:Timer = new Timer(750, 1);
timer.addEventListener(TimerEvent.TIMER_COMPLETE, flipBack);
timer.start();
stage.addEventListener(KeyboardEvent.KEY_DOWN, blindKeyboard);//added here
stage.addEventListener(KeyboardEvent.KEY_UP, blindKeyboard);//added here
mouseChildren = false;
}
}
function blindKeyboard(e:KeyboardEvent):void{ //added here function
e.preventDefault();
e.stopPropagation();
}
protected function flipBack(event:TimerEvent):void
{
_firstCard.gotoAndPlay("flipBack");
_secondCard.gotoAndPlay("flipBack");
_firstCard.addEventListener(MouseEvent.CLICK, checkCards);
_secondCard.addEventListener(MouseEvent.CLICK, checkCards);
_firstCard = _secondCard = undefined;
mouseChildren = true;
}

Answer 1

You could just have functions for adding/removing listeners :
function addListeners():void
{
// loop through and add the listeners for the cards
// add keyboard listeners
}
function removeListeners():void
{
// loop through and remove listeners from the cards
// remove keyboard listeners
}
Before you set the timer, you remove your listeners :
removeListeners();
Then in your flipback timer handler you just call the addListeners :
addListeners();

Answer 2

Try
stage.addEventListener(KeyboardEvent.KEY_DOWN, blindKeyboard);
stage.addEventListener(KeyboardEvent.KEY_UP, blindKeyboard);
function blindKeyboard(e:KeyboardEvent):void{
e.preventDefault();
e.stopPropagation();
}