Using course tools>>Collaboration tools>>Chat
The Chat toolbar appears at the top of the Chat window.
Click View to specify whether private messages should appear in the same or a different window.
Click Controls to specify which features to make available to active participants and to passive participants. You can also end the session, removing all the users from it.
Click Clear to clear your display only or the display of every user.
Click End to close the current Virtual Classroom session.