If you are new to ActionScript, or if you want to add simple interactivity without having to learn the ActionScript language and its syntax, you can use Script Assist in the Actions panel to help you add ActionScript to your FLA files.
Script Assist lets you build scripts by selecting items from the Actions toolbox. When you click an item once, its description appears at the upper right of the panel. When you double-click an item, it adds the item to the Actions panel Script pane.
In Script Assist mode, you can add, delete, or change the order of statements in the Script pane; enter parameters for actions in boxes above the Script pane; find and replace text; and view script line numbers. You can also pin a script—that is, keep a script in the Script pane when you click away from the object or frame.
Script Assist helps you avoid the syntax and logic errors a novice user might make. However, to use Script Assist you must become familiar with ActionScript, and know what methods, functions, and variables to use when creating your scripts. To learn about ActionScript, see Learning ActionScript 2.0 in Adobe Flash or Programming ActionScript 3.0.
For a video tutorial about Script Assist mode, see www.adobe.com/go/vid0131.
For a text tutorial about Script Assist mode, see Use Script Assist Mode on the Flash Tutorials page at www.adobe.com/go/learn_fl_tutorials.