function jget(tv)

        include 'parameter.par' 
#include "precision.com"
	include 'common.com'

c------------------------------------------------------------------------------
	
	if(tv.le.tmn)then
	   jget = 0
	   return
	endif

	if(tv.ge.tmx)then
	   jget = n
	   return
	endif

	do j=1,n-1
	   tc = temp(j)
	   tp = temp(j+1)
	   dp = tp-tv
	   dc = tc-tv
	   if(dc*dp.lt.0.0)then
	      jget = j
	      if(j.lt.1.or.j.gt.n-1)stop 'jget: bad j'
	      return
	   endif
	end do

	stop 'jget: unallowed exit'
	end

c------------------------------------------------------------------------------