The adone trigger occurs when an animation completes. It can be particularly useful for chaining together multiple actions across multiple objects.
Examples:
create animate me jump 5 5 200, astop; activate astart; adone noise whee
This action runs a 5-frame jump animation when the object is clicked on, and then plays the sound file "whee.wav" as soon as the animation is complete.
create animate me door 1 1 8000, astop; activate astart, visible off, solid off; adone visible on, solid on
This action paints the texture named door1 onto the object when it's loaded into the scene and sets up an 8-second animation timer. Clicking the object then causes it to turn invisible and non-solid, and to begin the 8-second animation timer. When the timer completes, the object is made visible and solid.