A breakpoint allows you to stop a movie running in the Flash Player at a specific line of ActionScript. You can use breakpoints to test possible trouble spots in your code. For example, if you've written a set of if..else if
statements and can't determine which one is executing, you can add a breakpoint before the statements and step through them one by one in the Debugger.
You can set breakpoints in the Actions panel or in the Debugger. Breakpoints set in the Actions panel are saved with the Flash document (FLA) file. Breakpoints set in the Debugger are not saved in the FLA file and are valid only for the current debugging session.
Note: To set breakpoints in external scripts, you must use the debugger panel.
To set or remove a breakpoint in the Actions panel, click in the left margin. You can also use the Debug Options button above the Script pane, use the Context menu, or press Control+Shift+B (Windows) or Command+Shift+B (Macintosh).
To set and remove breakpoints in the Debugger:
Once the Flash Player is stopped at a breakpoint, you can step into, step over, or step out of that line of code. (See Stepping through lines of code.) If you set a breakpoint in a comment or on an empty line in the Actions panel, the breakpoint is ignored.