anchor.diff:  </table>
   
   <script type="text/javascript">
  -  function tag_filter(url, event, newText, add) {
  +  function tag_filter(event) {
       event.preventDefault();
   
       var data = { tagName: "${topicListRequest.tag}"};
  +
  +    var el = $('#tagFavAdd');
  +    var add = !el.hasClass("selected");
   
       if (add) {
         data['add'] = 'add';
  
positive.code:     </div>
      <div class="nav-buttons">
        <ul>
          <c:if test="${isShowFavoriteTagButton}">
            <li>
              <c:url var="tagFavUrl" value="/user-filter">
                <c:param name="newFavoriteTagName" value="${topicListRequest.tag}"/>
              </c:url>
  
              <a id="tagFavAdd" href="${tagFavUrl}">В избранные теги</a>
            </li>
          </c:if>
          <c:if test="${isShowUnFavoriteTagButton}">
            <li>
              <c:url var="tagFavUrl" value="/user-filter"/>
  
              <a id="tagFavAdd" href="${tagFavUrl}">Удалить из избранного</a>
            </li>
          </c:if>
          <c:if test="${isShowIgnoreTagButton}">
            <li>
            <c:url var="tagIgnUrl" value="/user-filter">
  
negative.code:     data['csrf'] = "${fn:escapeXml(csrfToken)}";
  
      $.ajax({
        url: "/user-filter/favorite-tag",
        type: "POST",
        dataType: "json",
        data: data
  