ADAS Subroutine xxslen

      SUBROUTINE XXSLEN( CSTRNG , IFIRST , ILAST )
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: XXSLEN *********************
C
C  PURPOSE: TO IDENTIFY THE FIRST AND LAST NON-BLANK CHARACTER IN A
C           STRING. (IF INPUT STRING IS BLANK IFIRST=ILAST=0)
C
C  CALLING PROGRAM: GENERAL USE
C
C  SUBROUTINE:
C
C  INPUT : (C*(*)) CSTRNG   = INPUT STRING FOR INTERROGATION
C
C  OUTPUT: (I*4)   IFIRST   = BYTE POSITION OF FIRST NON-BLANK CHARACTER
C                             IN INPUT STRING.
C  OUTPUT: (I*4)   ILAST    = BYTE POSITION OF LAST  NON-BLANK CHARACTER
C                             IN INPUT STRING.
C
C          (I*4)   I        = GENERAL USE
C          (I*4)   ILEN     = LENGTH OF 'CSTRNG' STRING IN BYTES
C
C ROUTINES: NONE
C
C NOTE:
C
C
C AUTHOR:  PAUL E. BRIDEN (TESSELLA SUPPORT SERVICES PLC)
C          K1/0/37
C          JET EXT. 6023
C
C DATE  :  06/07/93
C
C-----------------------------------------------------------------------
C-----------------------------------------------------------------------
C
C-----------------------------------------------------------------------
      CHARACTER*(*)       CSTRNG
      INTEGER             IFIRST,      ILAST