text: 
  function appendCanvas(placeholder_id, title, initDrawing) {
      var canvasPlaceholder = d3.select("#"+placeholder_id);
      canvasPlaceholder.append("em").text(title);
      var canvas = canvasPlaceholder.append("canvas");
      canvas.text("Cannot display canvas. Sorry, this is only supported by modern browsers.");
      var ctx = canvas[0][0].getContext("2d");
      initDrawing(title, canvasPlaceholder, canvas, ctx);
  }
  