To Define an Event
Use events as markers in the timeline to arrange animation component timing. The default event, Start, specifies the time at the beginning of the animation. This default event always appears on the timeline. Follow these steps to define other events:
1. Click 
Event. The Event Definition dialog box opens.
Event. The Event Definition dialog box opens.2. Type a name for the event or accept the default name.
3. Type a time and select a reference event from the After list. The new event begins after the reference event and time. The time you enter can be negative with respect to the selected event, but cannot occur before the start time of the animation.
4. Click OK. An event symbol, with the name of the new event, appears in the animation timeline. If the event is referenced to an existing timeline component, a dotted line leads from the reference event to the new event.