circle.setAttribute("cy", pt.y);
      circle.setAttribute("r", 3);
      circle.setAttribute("fill", "blue");
      document.getElementById("test-body-content").appendChild(circle);

      pt = boxpl.getPointAtLength(0);
      document.getElementById("tp2").firstChild.data = "(" + pt.x + ", " + pt.y + ")";
      circle = document.createElementNS("http://www.w3.org/2000/svg", "circle");
      circle.setAttribute("cx", pt.x);
      circle.setAttribute("cy", pt.y);
      circle.setAttribute("r", 3);
      cir