integer function itchk (string)

      character*(*) string
      character*80 message

c returns the integer value from a character string of the form,
c               [blanks][sign][digits]digit
c  aborts if non-integer in string


      itchk = itch(string, ier)
      if (ier .ne. len(string)) then
        lenmes = 0
        call append ('Itchk: non integer value in ', message, lenmes)
        call append (string, message, lenmes)
        call abort (message(:lenmes))
      end if
      return
      end