// allow easy checking if an element is the descendant of another
(function($) {
    $.fn.extend({
        isChildOf: function(filter_string) {

            var parents = $(this).parents().get();

            for (j = 0; j < parents.length; j++) {
                if ($(parents[j]).is(filter_string)) {
                    return true;
                }
            }

            return false;
        }
    });
})(jQuery);