code: function openReply(id) {
      // Swap out the reply link for the hide link
      $('#rl' + id).hide();
      $('#cr' + id).show();
  
      // Add the reply li to the children ul.
      var div = $(renderTemplate(replyTemplate, {id: id})).hide();
      $('#cl' + id)
        .prepend(div)
        // Setup the submit handler for the reply form.
        .find('#rf' + id)
        .submit(function(event) {
          event.preventDefault();
          addComment($('#rf' + id));
          closeReply(id);
        })
        .find('input[type=button]')
        .click(function() {
          closeReply(id);
        });
      div.slideDown('fast', function() {
        $('#rf' + id).find('textarea').focus();
      });
    }
docs: Open a reply form used to reply to an existing comment.