1 10/20/83  read_mail request:  current, c
 2 
 3 Syntax:  c
 4 
 5 
 6 Syntax as an active request:  [c]
 7 
 8 
 9 Function:  prints the current message's message number; as an active
10 request, returns the current message's message number.
11 
12 
13 Notes:
14 If there is no current message, the active request will return the
15 value zero.