      SUBROUTINE X04AAF(I,NERR)
C     MARK 7 RELEASE. NAG COPYRIGHT 1978
C     MARK 7C REVISED IER-190 (MAY 1979)
C     MARK 11.5(F77) REVISED. (SEPT 1985.)
C     MARK 14 REVISED. IER-829 (DEC 1989).
C     IF I = 0, SETS NERR TO CURRENT ERROR MESSAGE UNIT NUMBER
C     (STORED IN NERR1).
C     IF I = 1, CHANGES CURRENT ERROR MESSAGE UNIT NUMBER TO
C     VALUE SPECIFIED BY NERR.
C
C     .. Scalar Arguments ..
      INTEGER           I, NERR
C     .. Local Scalars ..
      INTEGER           NERR1
C     .. Save statement ..
      SAVE              NERR1
C     .. Data statements ..
      DATA              NERR1/6/
C     .. Executable Statements ..
      IF (I.EQ.0) NERR = NERR1
      IF (I.EQ.1) NERR1 = NERR
      RETURN
      END
