subroutine FIT_REL(K0)
C       ----------------------
	include 'fit.inc'

	integer k0
	logical done
	integer n1,n2,k,i

C--      K0 = NUMBER OF PARAMETER TO BE RELEASED
C--	 K0 = 0 MEANS RELEASE ALL PARAMETERS

	if (k0 .eq. 0) then
	  n1=1
	  n2=nu
	elseif (k0 .le. 0 .or. k0 .gt. nu) then
	  write(isyswr,'(4X,A,I3)') 'Illegal parameter no.:',k0
	  return
	elseif (ififu .eq. 6 .and. k0 .gt. 2) then
	  write(isyswr,'(4X,A,I3)') 'Can not release this parameter'
	  return
	else
	  n1=k0
	  n2=k0
	endif

	write(isyswr,*)

	done=.false.
	do k=n1,n2
	  if (lcode(k) .le. 0) then
	    if (icsw(k) .lt. 0) then			! special correlation
	      if (k0 .ne. 0) then
	        i=icto(k)
	        icsw(i)=-1				! cor. parameter i
	        icto(i)=k
	        if (lcode(i) .gt. 0) lcode(i)=-lcode(i)
	        write(isyswr,'(4X,3A)') pnam(i),' depends now on ',pnam(k)
	        lcode(k)=-lcode(k)
	        if (lcode(k) .eq. 0) lcode(k)=1
	        if (icsw(k) .lt. 0) icsw(k)=0
	      endif
	    else
	      if (icsw(k) .eq. 0) then
	        write(isyswr,'(4X,2A)') pnam(k),' released'
	      else
	        write(isyswr,'(4X,2A)') pnam(k)
	1                ,' released from correlation'
	        icsw(k)=0
	      endif
	      lcode(k)=-lcode(k)
	      if (lcode(k) .eq. 0) lcode(k)=1
	      done=.true.
	    endif
	    if (ififu .eq. 1 .and. u(k) .eq. 0) then
	      if (mod(k,5) .eq. 1) then
	        u(k)=u(k+1)/10
	      elseif( mod(k,5) .eq. 2) then
	        u(k)=u(k-1)/10
	      endif
	    endif
	  elseif (k0 .ne. 0) then
	    write(isyswr,'(4x,2a)') pnam(k)
	1      ,' is not fixed or correlated'
	  endif
	enddo
	call extoin
	end