anchor.diff:      });
       html += '</tr></table>';
       return html;
  -  };
  -
  -  // - - - - - - - - - - - - - - - - - - - - - - - -
  -
  -  const makeIndexLeft = () => {
  -    return '' +
  -      '<button class="triangle button" id="prev-index">' +
  -        '<img src="/images/triangle_prev.gif" alt="move to previous diff"/>' +
  -      '</button>';
  -  };
  -
  -  // - - - - - - - - - - - - - - - - - - - - - - - -
  -
  -  const makeIndexRight = () => {
  -    return '' +
  -      '<button class="triangle button" id="next-index">' +
  -        '<img src="/images/triangle_next.gif" alt="move to next diff"/>' +
  -      '</button>';
     };
   
     // - - - - - - - - - - - - - - - - - - - - - - - -
  
positive.code:       <div id="download-button-container"></div>
        <div id="diff-filenames"></div>
      </td>
      <td>
        <div id="diff-content"></div>
      </td>
    </tr>
  
negative.code:     let html = '';
      let wasIndex = 0;
      html += '<table><tr valign="top">';
      $.each(param.events, (_n, event) => {
        const colour = event.colour;
        if (colour !== '') {
  