Subroutine:   REJECT

Purpose:      Reject user input.

Category:     USER-INTERFACE 

File:         srvreq.c

Author:       J.P. Terlouw

Use:          CALL REJECT( KEY, MESSAGE)

              KEY     The userinp keyword of which the values are to
                      be rejected. Type CHARACTER.

              MESSAGE informs the user about the rejection. (CHARACTER)
              
Example:      Here the servant task checks on the validity of the
              input and repeats the call to obtain the input if it
              was invalid.
              
              .
              WHILE (.TRUE.)                      infinite loop
                 NEL = USRREAL( VALUE,..., 'V=', 'TYPE V' )
                 IF (VALUE is valid)
                 THEN
                    XWHILE            leave loop
                 ELSE
                    CALL REJECT( 'V=', 'Invalid value' )
                 CIF
              CWHILE
              .
              
Updates:      Dec 17, 1990: JPT, document created.