Okay I commented the code for you guys guess I should have done that in the first place.

Anyway to answer the questions I caused,
The lamp timer analogy is perfect DallasNYC thank you for answering that one.
clearInterval tells flash to quit using the interval. Basically in this case we want to change the amount of time between blinks everytime the blinking happens, so to do this we have to reset the timer everytime the lamp comes on, thus the clearInterval.

In any other case clearInterval is used to tell flash to quit repeating an action, it saves CPU cycles, especially if whatever was affected is no longer visible. Say we used setInterval and had a function that moved something to the right each time it was called, well when the object goes off the right side of the stage we don't need to have flash move it anymore, so we tell it to stop with clearInterval.

I hope that clarifys its use a little bit
And like I said before the code isn't necessarily the best but it works.

If you have more questions email me at [email protected]
Good Luck,
Shawn