ActionScript 2.0 :: Mouse Trails On Command?

I stumbled upon a tutorial from a few years back. It basically set up a rolling text mouse trail.I altered it so I could start the mouse trail with a button, but have yet to figure out how to stop it.

Here is the code:

Code:
on (release){
Text = "It's a mouse trail!";
letters = Text.split("");
letterformat = new TextFormat();

[code]....

In the tutorial it mentions the 'for loop' in the code. Does this mean I can not stop it once it starts? I hope not. I'd really like to give the user an option for turning off the mouse trail if they find it obtrusive.