Flash authoring panels
The Actions panel
The Actions panel lets you create and edit ActionScript code for an object or frame. Selecting a frame, button, or movie clip instance makes the Actions panel active. The Actions panel title changes to Button Actions, Movie Clip Actions, or Frame Actions, depending on what is selected.
To display the Actions panel, select Window > Actions or press F9.
You better remember this shortcut because You will use it very often.
In more advanced articles You will learn how to use Action Scripts and Actions Panel.