common /fit/x,y,sigmay,npts,mode,a,sigmaa,b,sigmab,r
      double precision x,y,sigmay,a,sigmaa,b,sigmab,r
      integer npts,mode
      dimension x(50),y(50),sigmay(50)
1     type 100
      accept 101,npts
      if (npts.eq.0) goto 999
      type 102
      accept103,mode
      type 104
      do 10 i=1,npts
10    accept 105,x(i),y(i),sigmay(i)
      call linfit
      type 200,a,sigmaa
      type 201,b,sigmab
      type 202,r
      type 203
      goto 1
999   stop
100   format(' number of points='$)
101   format(i)
102   format(' mode='$)
103   format(i)
104   format('0input data:'/)
105   format(3d)
200   format(1x,'y-intercept = ',1pd20.5,3x,'(+/-)',3x,1pd20.5)
201   format(1x,'slope =       ',1pd20.5,3x,'(+/-)',3x,1pd20.5)
202   format(1x,'correlation = ',f20.5)
203   format('1')
      end