f the arrow, and then
      //again to the opposite side point
      ctx.lineTo(tox, toy);
      ctx.lineTo(tox-headlen*Math.cos(angle-Math.PI/7),
                 toy-headlen*Math.sin(angle-Math.PI/7));

      //draws the paths created above
      ctx.stroke();
      ctx.restore();
    };


    </script>
  </body>
</html>
