Timer With hitTest

[SChaput]

I am having many problems trying to get my timer working correctly using as2. I want the timer to start when the movie enters the second frame, the person watching the movie needs to see the timer incrementing, like a score, and then to stop once a hitTest has been detected.
Help is appreciated.
Thanks.

[Medyman]

The timer (will increase "seconds" by 1 every second):

var seconds:Number = 0;
function addTime() {
  seconds++;
  trace(seconds + " seconds have elapsed")
}

var interval = setInterval(addTime, 1000);

To shut it off:

clearInterval(interval);