check keyboard state without using KeyboardEvent in AS3

Is it possible to check for pressed keys without using the KeyboardEvent?

I have an ENTER_FRAME event setup called enterFrameHandler and I want to check within the function enterFrameHandler if any keys are pressed.

normally when using a KeyboardEvent I could check for keys easily using a switch that checks the KeyCode of the event, but in an ENTER_FRAME event this isn't possible for me.

Is there any other way of checking the keyboard's state within the ENTER_FRAME event?

UPDATE: I found this AS2 script:

onClipEvent (enterFrame) {
    if (Key.isDown(Key.LEFT)) {
        _x -= power;
    }
    if (Key.isDown(Key.RIGHT)) {
        _x += power;
    }
    if (Key.isDown(Key.UP)) {
        _y -=power;
    }
    if (Key.isDown(Key.DOWN)) {
        _y +=power;
    }
}

This seems to be doing what I want, but it's in AS2, does anyone know how to 'translate' this into AS3?

Store key states in a dictionary or object:

stage.addEventListener(KeyboardEvent.KEY_UP, keyHandleUp);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyHandleDown);

private var hash:Object = {};

private function keyHandleUp(event:KeyboardEvent):void {
    delete hash[event.keyCode];
}

private function keyHandleDown(event:KeyboardEvent):void {
    hash[event.keyCode] = 1;
}

private function isKeyDown(code:int):Boolean {
    return hash[code] !== undefined;
}