How can i take the number of a random process to use it in math´s and show the solution to the user?

Question

i wrote this function and i try to show the number of seconds the user was to early or to late to click the stopbutton to the user.
its about to hit stop intuitiv while in the background ther is a random number already made but the user dont know or see it.
the eyes opens in a random between 100 and 40000 millisec. if they open up the user should click stop without seeing them. so its intuitiv.
i just tryed.
this code is on the mc with the eyes to let them open randomly. it is on the second frame at the main time code. 1st frame is the start button and a small description. on the second the stop button and the closed eyes with the script down here as i already said. and on the 3rd frame is the end wher it should be shown to the user. thats how i tryed. please let me know any suggestions and or other solutions to my problem! If you need to see my flashfile to help me just let me know. i send it to you or something :-)
mic(at)hellrec.at
function randomRange(minNum:Number, maxNum:Number):Number
    return (Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum);
var myTimer:Timer = new Timer((randomRange(100, 40000)),1);
myTimer.addEventListener(TimerEvent.TIMER,openeyes1);
myTimer.start();
var duration:uint = getTimer();
function openeyes1(e:TimerEvent):void {
gotoAndPlay (26);
e.updateAfterEvent();

Answer 1

to save the number use:
function randomRange(minNum:Number, maxNum:Number):Number
    return (Math.floor(Math.random() * (maxNum - minNum + 1)) + minNum);
var randomNum:Number= randomRange(100, 40000);
var myTimer:Timer = new Timer(randomNum,1);
myTimer.addEventListener(TimerEvent.TIMER,openeyes1);
myTimer.start();
var duration:uint = getTimer();
function openeyes1(e:TimerEvent):void {
gotoAndPlay (26);
e.updateAfterEvent();
p.s. please mark helpful/correct responses.