module m_tecfld
contains
subroutine tecfld(fname,ii,jj,nr,fld)
   implicit none
   character(len=*), intent(in) :: fname
   integer,          intent(in) :: ii,jj,nr
   real,             intent(in) :: fld(ii,jj,nr)
   integer m,i,j
   logical lopen
   integer iunit
   character(len=100) fn

   do iunit=10,20
      inquire(unit=iunit,opened=lopen)
      if (.not.lopen) then
         fn(:)=' '
         fn(1:4)='tec_'
         fn(5:5+len_trim(fname))=trim(fname)
         fn(5+len_trim(fname):5+len_trim(fname)+4)='.dat'
         open(iunit,file=trim(fn),status='unknown')
            write(iunit,*)'TITLE = "',fname,'"'
            write(iunit,*)'VARIABLES = "i-index" "j-index" '
            write(iunit,'(5(a,i3,a))')(' "F',i,'"',i=1,nr)
            write(iunit,'(a,i3,a,i3,a)')' ZONE  F=BLOCK, I=',ii,', J=',jj,', K=1'
            write(iunit,'(30I4)')((i,i=1,ii),j=1,jj)
            write(iunit,'(30I4)')((j,i=1,ii),j=1,jj)
            do m=1,nr
               write(iunit,900)((fld(i,j,m),i=1,ii),j=1,jj)
            enddo
         close(iunit)
         exit
      endif
   enddo
 900 format(10(1x,e12.5))
end subroutine tecfld


end module m_tecfld