You may have noticed how I set up the movie file in the previous part. This is just to clear up some of the set up.
A) Create layers for each element of your UI. This will allow you to animate them, and lock them down later as you finish them.
B) Create a layer for actionscript. This makes it easy to find, and easy to label without arrows and what not getting in the way. I usually label it "as" in the movies inside the file, and "as_root" for the main one in the file.
C) Unless you want something to play or loop for ever, put a quick stop(); on the first line.
We're going to move on, implementing the one singular feature for now. Then we'll come back and look at spawning in new things.
I figured that you have some experience with Flash, so I'll assume you understand this. If you have questions, please ask it here.
If you have suggestions to clarify something or a better way of doing something, then please do so in the addendum. Thank you.