      subroutine istkin (nitems, itype)
c
c initializes the stack allocator, setting the length of the stack.
c
c error states -
c
c   1 - nitems .le. 0
c   2 - itype .le. 0 .or. itype .ge. 7
c
      logical init
c
      data init / .true. /
c
      if (nitems.le.0) call seterr (20histkin - nitems.le.0, 20, 1, 2)
c
      if (itype.le.0 .or. itype.ge.7) call
     1  seterr (33histkin - itype.le.0.or.itype.ge.7, 33, 2, 2)
c
      if (init) call i0tk00 (init, nitems, itype)
c
      return
c
      end