ActionScript 3.0 :: Access Vars Between Document Class And Other Classes?

For the example, there's a single FLA with a document class "main.as." In the public class main.as package, there is a public variable: "var example:String='example';." Inside of the FLA, there is one movie clip in the library and it is assigned a custom base class "sub.as." The movie clip is then placed on the first frame of the stage so its constructor is run at runtime and reads the value of example.

What is the proper way to get the value of "example" in the root document class? Using "root.example" in the sub.as class to target the document class returns an error and when I trace "root", I get "null." Main.example naturally throws an error because that's looking at the actual class and not the movie / stage its attached to.The round-about way I've done it before is to dynamically add the object in the library and pass in the root path when I create a new instance of it (example: submc:sub = new sub(this); ).Is there anyway to get back to the document class with a built-in method like root, etc?