1 UP
 This command is provided to move up in the directory hierarchy.
 
 Format:
 
      UP   [number_levels]
 
 Where number_levels specifies the number of levels to go up.  IF
 no value is specified 1 is assumed.
 
 The current subdirectory is placed on a stack which may be  used
 by  the  'DOWN'  command  as  a default.  If multiple levels are
 specified then each of the multiple  levels  is  placed  on  the 
 stack.
 
 This command gives no errors if there is no higher level.
