The session is in only one of two states: 
(1) Response mode
In response mode, the tunnelhack program is waiting for a specific response
from the client. The lower-right window contains the prompt and links for
responding to it, and the other actions are disabled.

(2) Action mode
The session is in Action mode when tunnelhack is prompting for the player's
action this turn. In this mode, the lower-right window contains a display
of the creatures and items in the room, and the "inventory" and "map" buttons
work.

(3) Listen mode
~~M Message
~~C Creature window
~~I Item window
~~V Inventory item
~~@ Map line
~~S Status line
~~R Room name
~~D Room description
~~- New AP
~~? Go into Response Mode
~~| Go into Action mode.
~~{ Setup list query
~~} End list query.
~~$ String query
~~* Character query (Length~~Prompt)
~~^ Boolean (y/n) query
~~+ NSEW query
~~! Error.