anchor.diff:                      <form id="subscribers_form" action="" method="post">
                           <div class="btn-toolbar bg-light" role="toolbar" aria-label="">
                               <div class="btn-group" role="group">
  -                                <button id="add_btn" class="navbar-brand btn-outline-info" type="submit" data-tooltip="tooltip" data-placement="top" title="New subscription">
  +                                <button id="add_btn" class="navbar-brand btn-outline-info" type="submit"
  +                                        data-tooltip="tooltip" data-placement="top" title="New subscription">
                                       <i class="fas fa-plus-circle fa-2x"></i>
                                   </button>
                               </div>
                               <div class="btn-group mr-2" role="group" aria-label="">
  -                                <button id="activate_btn" class="navbar-brand btn-outline-primary" type="submit" data-tooltip="tooltip" data-placement="top" title="Activate subscriptions">
  +                                <button id="activate_btn" class="navbar-brand btn-outline-primary" type="submit"
  +                                        data-tooltip="tooltip" data-placement="top" title="Activate subscriptions">
                                       <i class="far fa-play-circle fa-2x"></i>
                                   </button>
  -                                <button id="deactivate_btn" class="navbar-brand btn-outline-warning" type="submit" data-tooltip="tooltip" data-placement="top" title="Deactivate subscriptions">
  +                                <button id="deactivate_btn" class="navbar-brand btn-outline-warning" type="submit"
  +                                        data-tooltip="tooltip" data-placement="top" title="Deactivate subscriptions">
                                       <i class="far fa-pause-circle fa-2x"></i>
                                   </button>
                               </div>
                               <div class="btn-group" role="group">
  -                                <button id="remove_btn" class="navbar-brand btn-outline-danger" type="submit" data-tooltip="tooltip" data-placement="top" title="Remove subscriptions">
  +                                <button id="remove_btn" class="navbar-brand btn-outline-danger" type="submit"
  +                                        data-tooltip="tooltip" data-placement="top" title="Remove subscriptions">
                                       <i class="far fa-trash-alt fa-2x"></i>
                                   </button>
                               </div>
  
positive.code: <%@include file="_include.jsp" %>
  <html lang="en">
  <head>
      <%@include file="_head.jsp"%>
  </head>
  
  <body id="page-top">
  
negative.code:         reloadRssTable();
  
          function reloadRssTable() {
              $.getJSON(rootURL + '/${subscriber}', function (data) {
                  userData = data;
  
                  var rssTable = $('<table>')
                      .addClass('table table-hover')
                      .append('<thead>' +
                          '<tr>' +
                          '<th style="vertical-align: initial"><input type="checkbox" class="form-check-input" id="select_all_checkbox"/></th>' +
                          '<th>#</th>' +
                          '<th>rss</th>' +
                          '<th>status</th>' +
                          '<th>last polling date</th>' +
                          '<th>error message</th>' +
                          '<th>retry count</th>' +
                          '</tr></thead>')
                      .append('<tbody>');
  
                  $.each(data.rsslist, function (i, item) {
                      var tr = $('<tr>');
                      if (item.status === 'dead') {
                          tr.addClass('table-danger');
                      }
                      else if (item.status === 'offline') {
                          tr.addClass('table-warning');
                      }
                      else {
                          tr.addClass('table-light');
                      }
  
                      tr.append('<td><input type="checkbox" class="form-check-input" id="' + item.rss + '"/></td>'
                          + '<td>' + (i + 1) + '</td>'
                          + '<td><a href="' + item.rss + '" target="_blank">' + item.rss + '</a></td>'
                          + '<td>' + item.status + '</td>'
                          + '<td>' + item.lastPollingDate + '</td>'
                          + '<td>' + item.errorMessage + '</td>'
                          + '<td>' + item.retryCount + '</td>');
  
                      rssTable.append(tr);
                  });
                  $("#details").html(rssTable);
  
                  $("#select_all_checkbox").change(function (e) {
  