      SUBROUTINE FIL_IN(IUNIT,CFIL)
*
***** ***************************************************************
*
*---- Gecontroleerd opvragen invoerfile, naam bewaren!
*
*---- Bert Bleij & Flip Witte, LUW, 031094
*
***** ***************************************************************
*
      CHARACTER CFIL*35
      LOGICAL AANW
*
      GOTO 20
10    WRITE(6,900)'Fout; invoerfile is: '
20    READ(5,910,ERR=10)CFIL
      INQUIRE(FILE=CFIL,EXIST=AANW)
      IF (.NOT.AANW) GOTO 10
      OPEN(IUNIT,FILE=CFIL,STATUS='OLD')
*
900   FORMAT(A35,$)
910   FORMAT(A35)
*
      RETURN
      END