https://marcoballetta.com/wp-content/themes/givingpress-lite/js/navigation.js?ver=20130729

1/**
2* navigation.js
3* Licensed under the GPLv2 license.
4* Handles toggling the navigation menu for small screens.
5*/
6( function() {
7
8	var container, button, menu, holder;
9
10	container = document.getElementById( 'navigation' );
11	if ( ! container )
12		return;
13
14	button = document.getElementsByClassName( 'menu-toggle' )[0];
15	if ( 'undefined' === typeof button )
16		return;
17
18	menu = container.getElementsByTagName( 'ul' )[0];
19
20	// Hide menu toggle button if menu is empty and return early.
21	if ( 'undefined' === typeof menu ) {
22		button.style.display = 'none';
23		return;
24	}
25
26	holder = container.getElementsByTagName( 'div' )[0];
27	if ( 'undefined' === typeof holder )
28		return;
29
30	button.onclick = function() {
31
32		if ( -1 == menu.className.indexOf( 'mobile-menu' ) )
33			menu.className = 'menu';
34
35		if ( -1 != button.className.indexOf( 'toggled-on' ) ) {
36			button.className = button.className.replace( ' toggled-on', '' );
37			menu.className = menu.className.replace( ' toggled-on', '' );
38			menu.className = menu.className.replace( 'mobile-menu', 'menu' );
39			holder.className = holder.className.replace( 'mobile-menu', 'menu' );
40			container.className = container.className.replace( 'main-small-navigation', 'navigation-main' );
41		} else {
42			button.className += ' toggled-on';
43			menu.className += ' toggled-on';
44			menu.className = menu.className.replace( 'menu', 'mobile-menu' );
45			holder.className = holder.className.replace( 'menu', 'mobile-menu' );
46			container.className = container.className.replace( 'navigation-main', 'main-small-navigation' );
47		}
48	};
49
50} )();