Sticky Header on Scroll

    var showHeaderAt = 300;

    var win = $(window);
    var body = $('body');

    var sticky_visible = false;

    win.on('scroll', function(){

        if(win.scrollTop() > showHeaderAt) {

            if (sticky_visible == false) {
                body.addClass('header-stuck');
                setTimeout(function() {
                    body.addClass('fixed_active');
                }, 100);
                sticky_visible = true;
            }
        }
        else if (sticky_visible == true) {
            body.removeClass('fixed_active');
            body.removeClass('header-stuck');
            sticky_visible = false;
        }

    });