[jQuery] Plugin does not work in IE7 and IE6

This script does not work for IE7 and IE6, it gives an error on line
12, sign 3 and 5:

(function($) {
        alert('1');

        var settings = {
                effect: {
                        duration: 100,
                },
        };

        $.fn.menu = function() {
                alert('2');

                $(this).each(function() {
                        alert('3');
                        $(this).find('/li').hover(function() {
                                alert('4');
                                showItem($(this));
                        }, function() {
                                alert('6');
                                hideItem($(this));
                        });
                });

                return this;
        };

        function showItem(item) {
                alert('5');
                item.find('/a').addClass('active');

                item.find('/ul:hidden').slideDown(settings.effect.duration);
        };

        function hideItem(item) {
                alert('7');
                item.find('/a').removeClass('active');

                item.find('/ul:visible').slideUp(settings.effect.duration);
        };
})(jQuery);


Any idea what's wrong?
Thanks so much! =o)