Hide Navigation on scroll - jQuery

hide_nav_on_scroll_jquery.js

//Performance - caches a jQuery object containing the header element
var header = $(".yourHeaderClass");
//  use prevScroll value to determine scroll direction
var prevScroll = $(window).scrollTop();

$(window).scroll(function() {
    var scroll = $(window).scrollTop();

    // Add class after scrolling 300px from top, remove class when scrolling up
    // Remove (scroll > prevScroll) to hide nav both on scroll Up and scroll down
    if ((scroll >= 300) && (scroll > prevScroll)) {
        header.addClass("hideNav");
    } else {
        header.removeClass("hideNav");
    }
    prevScroll = scroll;
});