Actionscript 3: How to detect when a button isn't pressed in time? - actionscript-3

Question

Okay, this is another question for the game I am making. I am putting together a second level, where you need to press a long series of keys at the right time. Pressing them too early or too late results in failure. What I need to know is how to detect when a key ISN'T pressed, when it should have been. This is what I have so far:
var count3:Number = 23;
var myTimer3:Timer = new Timer(1000, count3);
var timeLeft3:Number = count3;
var buttonPressed:Boolean = false;
var btnCounter:Number = 2;
var btnTimer:Timer = new Timer(1000, btnCounter);
myTimer3.addEventListener(TimerEvent.TIMER, countdown3);
myTimer3.start();
btnTimer.addEventListener(TimerEvent.TIMER, btnCountdown);
btn1.addEventListener(MouseEvent.CLICK, buttonPress);
btn1.visible = false;
btn2.visible = false;
btn3.visible = false;
btn4.visible = false;
btn5.visible = false;
btn6.visible = false;
btn7.visible = false;
btn8.visible = false;
btn9.visible = false;
function countdown3(event:TimerEvent): void {
if (((count3)-myTimer3.currentCount)==20) {
btn1.visible = true;
btnTimer.start();
} else if (((count3)-myTimer3.currentCount)==19) {
btn1.visible = true;
} else {
btn1.visible = false;
}
}
function btnCountdown(event:TimerEvent):void {
if (((btnCounter)-btnTimer.currentCount)==0) {
if (buttonPressed = true) {
btnTimer.stop();
} else {
gotoAndStop(2);
}
}
}
function buttonPress (event:MouseEvent): void {
buttonPressed = true;
}
For some reason, it won't do anything when btnCounter hits 0. If someone could help me sort this out, that would be awesome. Thanks.
N.B. This is a personal project, I am just learning actionscript

Answer 1

Start a timer for the time duration when the button is supposed to be pressed (for example, if the button must be pressed within 2 seconds, set the timer's interval to 2 seconds).
Then create a global Boolean variable (or class member variable, however your scene is set up) and set it to false initially. When the button is pressed, set this variable to true and disable the timer.
If the timer fires and this variable is false, it means that it hasn't been disabled by the button so the user didn't click the button within 2 seconds.
Don't use terribly short times - timers are not very accurate and processor speed may have an effect on their duration. (Human reaction times aside.)