anchor.diff:    // refresh [<] avatar [>]
     //-----------------------------------------
   
  -  var refreshAvatarControls = function() {
  +  const refreshAvatarControls = () => {
       refreshPrevAvatarHandler();
       refreshAvatarImage();
       refreshNextAvatarHandler();
     };
   
  -  var refreshAvatarImage = function() {
  +  const refreshAvatarImage = () => {
       $('#avatar').parent().html(makeAvatarImageHtml());
     };
   
  -  var makeAvatarImageHtml = function() {
  +  const makeAvatarImageHtml = () => {
       return '<img id="avatar" src="/images/avatars/' + param.avatar + '.jpg"/>';
     };
   
  -  var refreshPrevAvatarHandler = function() {
  +  const refreshPrevAvatarHandler = () => {
       refreshAvatarHandler('prev', param.prevAvatar);
     };
   
  -  var refreshNextAvatarHandler = function() {
  +  const refreshNextAvatarHandler = () => {
       refreshAvatarHandler('next', param.nextAvatar);
     };
   
  -  var refreshAvatarHandler = function(id, name) {
  -    var title = function() {
  -      var text = 'Click to review ' + name + "'s ";
  +  const refreshAvatarHandler = (id, name) => {
  +    const title = () => {
  +      const text = 'Click to review ' + name + "'s ";
         return text + (inDiffMode() ? 'diffs' : 'current code');
       };
       $('#' + id + '-avatar')
         .attr('disabled', name == '')
         .attr('title', title())
         .unbind('click')
  -      .bind('click', function() {
  +      .bind('click', () => {
           param.avatar = name;
           if (inDiffMode()) {
             show(1);
  
positive.code:   // refresh traffic-lights
    //-----------------------------------------
  
    var refreshTrafficLights = function() {
      var trafficLights = $('#review-traffic-lights');
      trafficLights.html(makeTrafficLightsHtml(param.lights));
      $.each($('img[src$="_gap.png"]'), function(_, light) {
        var index = $(this).data('index');
        var tag = $(this).data('tag');
        $(this)
          .attr('title', toolTip(index))
          .click(function() { show(tag); });
      });
    };
  
    var makeTrafficLightsHtml = function(lights) {
      var html = '';
      var index = 1;
      var lastColour = '';
      html += '<table><tr>';
      $.each(lights, function(n, light) {
        var barGap = (param.nowTag == light.number) ? 'bar' : 'gap';
        html +=
          "<td><div class='traffic-light'>" +
            "<img src='/images/bulb_" + light.colour + '_' + barGap + ".png'" +
  
negative.code:     filename: "<%= @filename %>"
    };
  
    cd.setReviewDialogData = (id, avatar, wasTag, nowTag, filename) => {
      param = {
              id:id,
          avatar:avatar,
          wasTag:wasTag,
          nowTag:nowTag,
        filename:filename
      };
      reviewRefresh();
    };
  
    //-----------------------------------------
    // refresh diff? [x]
    //-----------------------------------------
  
    const refreshDiffCheckBox = () => {
      diffCheckBox()
        .attr('checked', inDiffMode())
        .unbind('click')
        .bind('click', () => { show(param.nowTag); });
    };
  
    const diffCheckBox = () => {
      return $('#diff-checkbox');
    };
  
    const inDiffMode = () => {
      return param.wasTag != param.nowTag;
    }
  
  