To create controls and transitions for screens, use behaviors. Controls enable the flow between screens—for example, you can go to another screen, hide a screen, or show a screen. Transitions create visual animations that play as the Flash document display changes from one screen to another.
Behaviors are built‑in ActionScript scripts that you add to an object, such as a screen, to control that object. Behaviors let you add the power, control, and flexibility of ActionScript coding to your document without having to create the ActionScript code yourself. Behaviors are available for a variety of objects in Flash, including movie clips, text fields, and video and sound files.
To learn more about creating screen-based documents that use ActionScript, see "About organizing code for screens in" in Using ActionScript 2.0 Components.