anchor.diff:        determineFrequencyClass(value);
         month_label = getMonthLabel(key);
         // console.log("key: " +key + ", value: " + value + " month label: " + month_label);
  -
  -      var cell = $('<td class="su-wayback-m-frequency ' + freq_class + '" data-toggle="tooltip" data-placement="top" data-container="body" data-year="' + target_year + '" data-key="' + key + '" data-original-title="' +  month_label + " " + target_year + ': ' + value +  ' captures" title=""><div style="opacity: 0;">&nbsp;</div></td>')
  +      if (freq_class.indexOf("captures")>=0) {
  +        // console.log("cell has: " + freq_class);
  +        var cell = $('<td class="su-wayback-m-frequency ' + freq_class + '" data-toggle="tooltip" data-placement="top" data-container="body" data-year="' + target_year + '" data-key="' + key + '" data-original-title="' +  month_label + " " + target_year + ': ' + value +  ' captures" title=""><div style="opacity: 0;">&nbsp;</div></td>');
  +      } else {
  +          var cell = $('<td class="su-wayback-m-frequency ' + freq_class + '""><div style="opacity: 0;">&nbsp;</div></td>');
  +      }
         $("#su-wayback-m-month-data").append(cell);
           $("[data-toggle='tooltip']").tooltip();
       });
     });
     
     // When a month is clicked, create cells for the DAYS visualization.
  -  $(document).on('click', '#su-wayback-m-month-data td', function () {
  +  $(document).on('click', '#su-wayback-m-month-data td.su-wayback-m-captures', function () {
       $("#su-wayback-m-month-data td > div").css("opacity", "0");
       $(this).find("div").css("opacity", "1");
       $(".su-wayback-m-day-display").css("display", "block");
  
positive.code: 
    function determineFrequencyClass(freq) {
      if (freq == 1) {
        freq_class = "su-wayback-m-low";
      } else if ((freq > 1) && (freq <= 3 )) {
        freq_class = "su-wayback-m-low-medium";
      } else if ((freq > 3) && (freq <= 5 )) {
        freq_class = "su-wayback-m-medium";
      } else if ((freq > 5) && (freq <= 7 )) {
        freq_class = "su-wayback-m-medium-high";
      } else if (freq > 7) {
        freq_class = "su-wayback-m-high";
      } else {
        freq_class = "";
      }
  
negative.code:       // convert day value to int from string
        determineFrequencyClass(parseInt(day_value, 10));
        var day_label = i + 1; // adjust for zero-based index; days start with 1
        if (freq_class.indexOf("captures")>=0) {
          var cell = $('<td class="su-wayback-m-frequency ' + freq_class + '" data-toggle="tooltip" data-placement="top" data-container="body" data-original-title="' + month_label + " " + day_label + ", " + target_year + ': ' + day_value +  ' captures" title=""><a href="<%= replayPrefix %>'+target_year+target_month+day_label+'120000/'+'<%=searchUrlSafe%>" style="z-index: 100001;"><div style="opacity: 0;">&nbsp;</div></a></td>');
        } else {
            var cell = $('<td class="su-wayback-m-frequency ' + freq_class + '"><div style="opacity: 0;">&nbsp;</div></td>');
        }
        $("#su-wayback-m-day-data").append(cell);
        $("[data-toggle='tooltip']").tooltip();
      }
  