You can also manage room allocation directly in the timetable window. Use the <Allocate/delete this room> (1) button to allocate rooms to scheduled periods or to delete already scheduled rooms (2,3).
Allocating rooms for block periods / all lesson periods
If you wish perform room allocation to a block of periods or to all periods of a lesson you can make the appropriate selection in the selection box in the top left.
Check the option "Also show occupied rooms" in the "Allocate/delete this room" dialogue if, in addition to the available rooms, you wish to list all those rooms that are not available at the time in question. They are indicated by the "Occupied" flag. Assigning an occupied room to a lesson, you can override the obstructing room, generate a clash or swap the rooms.