Changing Secondary Actor Elements
We use the car parking example.

The cells on ActorII column are clickable. The user only needs one mouse click. To add a secondary actor and its pre/poststate for event one, the user would click on that event's ActorII cell. The following dialog shows:

The user can select the desired actor, prestate and poststate. Pressing Commit will add them to the event. To clear (or delete) actorII elements from an event, the user should click Reset instead of commit button.