$(document).ready(function () {

            $('#accordion li').click(function () {

                //slideup or hide all the Submenu
                $('#accordion li').children('ul').slideUp('fast');

                //remove all the "Over" class, so that the arrow reset to default
                $('#accordion li > a').each(function () {
                    if ($(this).attr('rel') != '') {
                        $(this).removeClass($(this).attr('rel') + 'Over');
                    }
                });

                //show the selected submenu
                $(this).children('ul').slideDown('fast');

                //add "Over" class, so that the arrow pointing down
                $(this).children('a').addClass($(this).children('li a').attr('rel') + 'Over');

            });

        });