http://mindofahitchhiker.com/wp-content/themes/inkness/js/navigation.js?ver=20120206

1/**
2 * navigation.js
3 *
4 * Handles toggling the navigation menu for small screens.
5 */
6 
7( function() {
8	var container, button, menu;
9
10	container = document.getElementById( 'site-navigation' );
11	if ( ! container )
12		return;
13
14	button = container.getElementsByTagName( 'h1' )[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	if ( -1 === menu.className.indexOf( 'nav-menu' ) )
27		menu.className += ' nav-menu';
28
29	button.onclick = function() {
30		if ( -1 !== container.className.indexOf( 'toggled' ) )
31			container.className = container.className.replace( ' toggled', '' );
32		else
33			container.className += ' toggled';
34	};
35} )();