Linking a Movie Clip to external ActionScript code
In the Library, right-click on your movie clip obejct and select Linkage from the pop-up options.
In the dialog, fill in the name of your .as file (without the .as) in the AS 2.0 Class box. (In this example: "Crow") Close the Properties dialog. The example above links mcCrow to an ActionScript class file called Crow.as.