character xlab*20,ylab*20,header*50
      real m(1000),t(1000)
      character*99 dummy

      open(unit=1,name="sheet3Q4.dat",status="old")

      read(1,5) dummy
 5    format(a)
      i=1
 10   read(1,*,end=20) m(i),t(i)
      i=i+1
      go to 10

 20   continue
      n=i-1

      xmax=-1
      ymax=-1
      xmin=1e33
      ymin=1e33

        CALL PGBEGIN(0,'?',1,1) 
        CALL PGSCI(1)
        CALL PGSLS(1)

        do i=1,n
           if(m(i).gt.xmax) xmax=m(i)
           if(t(i).gt.ymax) ymax=t(i)
           if(m(i).lt.xmin) xmin=m(i)
           if(t(i).lt.ymin) ymin=t(i)
        enddo
        call pgenv(xmin,xmax,ymin,ymax,0,1)  

        write(xlab,100)
 100     format('Mass')
        write(ylab,200)
 200    format('Log Temperature')
        write(header,300)
 300    format(' Sheet3 Q4 ')
        call pglabel(xlab, ylab, header)

        call pgline(n,m,t)
        call pgend

        end