subroutine int_Bz(val,eval)
      
      implicit none

      integer i,n
      parameter(n=1101)
      double precision temp, norm
      double precision val,eval,slop,y_int
		common/bfield/temp(1101),norm(1101)

c      write (*,*) 'Give z Position (mm)'
c      read (*,*) val
     

c	write(6,*) temp(1), norm(1)
c	write(6,*) temp(2), norm(2)
c	write(6,*) temp(1100), norm(1100)
c	write(6,*) temp(1101), norm(1101)
*
      do i=1,n-1
         if(val.lt.temp(1).or.val.gt.temp(n)) then
            write(*,*) val,temp(1),temp(n)
            write(*,*) 'z value is out of range ... intBz code'
            stop
         elseif(val.eq.temp(i)) then
            eval = norm(i)
         elseif(val.eq.temp(i+1)) then
            eval = norm(i+1)
         elseif(val.gt.temp(i).and.val.lt.temp(i+1)) then
            slop = (norm(i+1)-norm(i))/(temp(i+1)-temp(i))
            y_int = norm(i) - slop*temp(i)
            eval = slop*val+y_int
            goto 100 !-KG
         else
            continue
         endif
      enddo

 100  eval = eval*1.236 !magnify intBz. Elog sim. post 11 -KG 
c      write (*,*) 'Bz_INT = ', eval

      return
      end