Functions, exchanging information

I have nested functions, I have removed most of the code.

function QA(event:MouseEvent):void {

function reportKeyDown2(event:KeyboardEvent):void {
trace("Key Pressed: " + String.fromCharCode(event.charCode) +
" (Key code: " + event.keyCode + ")");
if (event.keyCode == 81 || event.keyCode == 73) {
keyNote = "C";
:
More code
}
stage.addEventListener(KeyboardEvent.KEY_DOWN, reportKeyDown2);
}

btStart.addEventListener(MouseEvent.CLICK,QA);


I am not very familiar with functions - could anyone explain how I can modify this to exchange information between functions.
E.g. pass the "Key pressed" to the outer function. Is there a useful text on ActionScript 2 (CS3). While working with it is interesting, it is also a constant frustration, as it is hard to find solutions to the problems that arise. At distance resolution has failed to resolve any of my issues so far.
Thanks