ActionScript has changed considerably with each release of the Macromedia Flash authoring tools and Flash Player. When you create content for Macromedia Flash Player 8, you can use the full power of ActionScript. You can still use Flash 8 to create content for earlier versions of Flash Player, but you can’t use every ActionScript element.
This chapter provides guidelines to help you write scripts that are syntactically correct for the player version you are targeting.
You can review surveys for Flash Player version penetration on the Macromedia website; see www.macromedia.com/software/player_census/flashplayer/.
When you write scripts, ...