I don't use the timeline at all anymore - I think that's what you're asking?
In the properties Tab
click on the background so the document comes up in the Properties Tab
There is a field there called 'Class'
Enter in something like 'Main'
in the editor, create a file call Main.as (don't put Main.as in the Class field. And then the .fla will start with that file when it compiles.
Open a new flash project and put this in Main.as to test:
package { import flash.display.Sprite; public class Main extends Sprite {
// graphic element exported for action script in the .fla private var myMovieClip:MCinFLA; public function Main() { trace("Start Main" // create new graphic object this.myMovieClip = new MCinFLA(); // add object to the stage this.addChild(this.myMovieClip); // position the graphic this.myMovieClip.x = 100; this.myMovieClip.y = 100; } } }
Create the MCinFLA on the stage, make it a symbol and click on the Export for ActionScript button
There are also a ton of tutorials pretty much everywhere on what to do on this - google it.
The first is the Document Class which is linked by typing it in some box within a normal Fla file its in the properties box but you must create the AS file first. The other is creating a Movieclip class, when you create a movie clip for an Fla you can set "export for Actionscript", if you save a AS file in the same folder as the Fla it will be able to access it without writing a file path in the code, theres also a setting in flash that allows you to link custom classes, which I don't know how yet...