INTEGER FUNCTION LEN_TRIM(STRING)
C
C Return actual length of supplied string,
C excluding trailing blanks or zero if blank.
C
C STRING = String to search
C
      CHARACTER*(*) STRING
C
      DO 100 IPOS = LEN(STRING),1,-1
        IF (STRING(IPOS:IPOS).NE.' ') THEN
            LEN_TRIM = IPOS
            RETURN
        ENDIF
  100 CONTINUE
C
C String is blank
C
      LEN_TRIM = 0
      RETURN
      END