I have made a drop down menu system for a responsive website, but for some reason IE8 does not like the following code:

$(".menu-toggle").on('click', function (e) {

        $("#main-nav a[class^='menu-item']").each(function(i) {

            if ($(this).hasClass("menu-item-on")) {

                $(this).removeClass("menu-item-on");

            }

            else  {

                $(this).addClass("menu-item-on");

            }

        });

        e.preventDefault;

    });

It looks like it is adding the menu-item-on class then quickly removing it again! It seems to be working fine in IE9 and 10.

Can anybody help me here?