ADAS Subroutine xxstuc

      SUBROUTINE XXSTUC( STRING )
C
C
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: XXSTUC *********************
C
C  PURPOSE: ENSURES ALL LETTERS IN INPUT STRING ARE UPPER CASE.
C
C  CALLING PROGRAM: GENERAL USE.
C
C  I/O   : (C*(*)) STRING = STRING.
C
C          (I*4)  IDIFF   = DIFFERENCE IN CODES BETWEEN LOWER AND UPPER
C                           CASE LETTER.
C          (I*4)  I       = LOOP INDEX.
C
C ROUTINES: NONE
C
C AUTHOR:  JONATHAN NASH (TESSELLA SUPPORT SERVICES PLC)
C          K1/0/81
C          JET EXT. 5183
C
C DATE:    26/11/93
C
C-----------------------------------------------------------------------
C
C----------------------------------------------------------------------
      CHARACTER*(*)       STRING