subroutine fit_help(topic)
c	--------------------------

	implicit none
	character*(*) topic

	integer lun, l, tl, iostat
	character line*132, tpc*32

	print *
	call str_upcase(tpc, topic)
	if (tpc .eq. ' ') tpc='MAIN'
	call str_trim(tpc, tpc, tl)
	call sys_get_lun(lun)
	call sys_getenv('FIT_HELP_FILE', line)
	call sys_open(lun, line, 'r', iostat)
	if (iostat .ne. 0) goto 991
1	rewind lun
10	read(lun, '(a)',end=90) line
	call str_trim(line, line, l)
	if (line(1:1) .ne. '=') goto 10
	call str_upcase(line, line)
	if (index(line,'='//tpc(1:tl)) .eq. 0) goto 10
11	read(lun, '(a)',end=80) line
	call str_trim(line, line, l)
	if (line(1:1) .ne. '=') then
	  print *,line(1:l)	
	  goto 11
	endif
80	goto 99

90	print *,'no help available on keyword: ',topic

99	close(lun)
991	call sys_free_lun(lun)
	end