fixed nav menu

how to fix menu
add this css
.f-nav{ z-index: 9999; position: fixed; left: 0; top: 0; width: 100%;} 

after add jquery you have to add the following javascript code
following   "menu" is the div which is fixed when you scroll


jQuery("document").ready(function($){
	
	var nav = $('.menu');
	
	$(window).scroll(function () {
		if ($(this).scrollTop() > 136) {
			nav.addClass("f-nav");
		} else {
			nav.removeClass("f-nav");
		}
	});
 
});