jQuery Sticky Navigation for my reference

sticky-navigation

/**
 * Sticky Navigation
 * 
 * @returns {undefined}
 */
$( function () {

	// grab the initial top offset of the navigation 
	var sticky_navigation_offset_top = $( '#rtp-primary-menu' ).offset().top - 4;

	// our function that decides weather the navigation bar should have "fixed" css position or not.
	var sticky_navigation = function () {
		var scroll_top = $( window ).scrollTop(); // our current vertical position from the top

		// if we've scrolled more than the navigation, change its position to fixed to stick to top,
		// otherwise change it back to relative
		if ( scroll_top > sticky_navigation_offset_top ) {

			if ( ! $( '#rtp-primary-menu' ).hasClass( 'rtp-fixed-nav' ) ) {
				$( '#rtp-primary-menu' ).addClass( 'rtp-fixed-nav' );
			}

		} else {

			if ( $( '#rtp-primary-menu' ).hasClass( 'rtp-fixed-nav' ) ) {
				$( '#rtp-primary-menu' ).removeClass( 'rtp-fixed-nav' );
			}

		}
	};

	// run our function on load
	sticky_navigation();

	// and run it again every time you scroll
	$( window ).scroll( function () {
		sticky_navigation();
	} );

} );