anchor.diff:          this.refs.revieweeTable.clearCheckboxes();
         }
   
  -      document.getElementById('working').style.display = '';
  +      jQuery('#working').css('display', '');
   
         jQuery.ajax({
           url: '<%= populate_assignment_peer_reviews_path %>',
           method: 'GET',
           dataType: 'json',
           success: function(data) {
  -          document.getElementById('working').style.display = 'none';
  +          jQuery('#working').css('display', 'none');
             this.clearSelectedFields();
             this.setState({
               reviewerGroups: data[0],
  
positive.code:         }.bind(this),
  
          error: function(xhr, status, text) {
            var error = text + ': ' + xhr.responseText;
            this.props.setErrorMessage(error);
          }.bind(this)
  
negative.code:         return;
        }
  
        jQuery('#working').css('display', '');
  
        jQuery.ajax({
          method: 'POST',
          url: '<%= assign_groups_assignment_peer_reviews_path %>',
          data: dataToSend,
  
          success: function(data) {
            jQuery('#working').css('display', 'none');
            this.props.clearSelectedFields();
            this.props.refresh();
            this.setState({ error: null });
  