Setting up TimeLine Editor actions

You can also use the TimeLine Editor to add actions. Add actions to the action track of the TimeLine Editor by Ctrl-clicking (Windows) or Command-clicking (Mac OS). Unlike the onload and link actions, Timeline actions are not triggered by event handlers but rather by the timeline sequence. In this way you can initiate time-based actions or actions which interact with a given scene.

Using Actions > Setting up actions > Setting up TimeLine Editor actions