https://barr-milton.org/wp-content/themes/natural/js/navigation.js?ver=20130729

1/**
2* navigation.js
3*
4* Handles toggling the navigation menu for small screens.
5*/
6( function() {
7	var container = document.getElementById( 'navigation' ),
8		button = container.getElementsByClassName( 'menu-toggle' )[0],
9		menu = container.getElementsByTagName( 'ul' )[0];
10		holder = container.getElementsByTagName( 'div' )[0];
11
12	if ( undefined == button || undefined == menu )
13		return false;
14
15	button.onclick = function() {
16		if ( -1 == menu.className.indexOf( 'mobile-menu' ) )
17		menu.className = 'menu';
18
19		if ( -1 != button.className.indexOf( 'toggled-on' ) ) {
20			holder.className += ' sf-js-enabled';
21			button.className = button.className.replace( ' toggled-on', '' );
22			menu.className = menu.className.replace( ' toggled-on', '' );
23			menu.className = menu.className.replace( 'mobile-menu', 'menu' );
24			holder.className = holder.className.replace( 'mobile-menu', 'menu' );
25			container.className = container.className.replace( 'main-small-navigation', 'navigation-main' );
26		} else {
27			button.className += ' toggled-on';
28			menu.className += ' toggled-on';
29			menu.className = menu.className.replace( 'menu', 'mobile-menu' );
30			holder.className = holder.className.replace( 'menu', 'mobile-menu' );
31			holder.className = holder.className.replace( 'sf-js-enabled', '' );
32			container.className = container.className.replace( 'navigation-main', 'main-small-navigation' );
33		}
34	};
35
36	//Untoggle menu on screen resize
37	window.addEventListener("resize", function() {
38		if ( window.innerWidth > 767 ) {
39			button.className = button.className.replace( ' toggled-on', '' );
40			menu.className = menu.className.replace( ' toggled-on', '' );
41			menu.className = menu.className.replace( 'mobile-menu', 'menu' );
42			holder.className = holder.className.replace( 'mobile-menu', 'menu' );
43			container.className = container.className.replace( 'main-small-navigation', 'navigation-main' );
44		}
45
46	});
47
48	// Hide menu toggle button if menu is empty.
49	if ( ! menu.childNodes.length )
50		button.style.display = 'none';
51} )();