Mouse Wheel and Defining Movie Clip SIze

[RLW]

Hi,

I inherited a Flash usability problem:

It's a self assessment test created in Flash. I think it was originally built using individual flash files for each question and arrays.

Now it has been modified slightly.
Each question is in it's own movie clip and the whole test (all the questions) is in a container clip.

When the user checks a box they can no longer scroll using the MouseWheel on a PC.

I solved the problem using this AS I found and tweaked:

----------
// Creating the listener object

mouseListener = new Object();

// Create onMouseWheel function

mouseListener.onMouseWheel = function (delta) {
mcForMouseWheel._y += delta*8;
}

// Registering the listener to the Mouse object

Mouse.addListener(mouseListener);
---------

However, although this solves the problem of not being able to scroll. Now userscan scroll up and down to infinity and back.

Although I am new to AS(primarily worked with Flash as a designer), I am assuming I have to define the container movie clip dimensions somehow? I tried doing this several ways but so far have been unsuccessful.
If anyone can help with some sample code, it would be greatly appreciated.

P.S. Still using ActionScript 2, so if the fix is ActionScript 3 let me know.

Thanks,
RLW