code: function getChildren(ul, recursive) {
      var children = [];
      ul.children().children("[id^='cd']")
        .each(function() {
          var comment = $(this).data('comment');
          if (recursive)
            comment.children = getChildren($(this).find('#cl' + comment.id), true);
          children.push(comment);
        });
      return children;
    }
docs: Get the children comments from a ul. If recursive is true,
  recursively include childrens' children.