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