gistfile1.js

/**
 * navigation.js
 *
 * Handles toggling the navigation menu for small screens.
 */
( function() {
	var button = document.getElementById( 'site-navigation' ).getElementsByTagName( 'h3' )[0],
	    menu   = document.getElementById( 'site-navigation' ).getElementsByTagName( 'ul' )[0];

	button.onclick = function() {
		if ( button.className.match( new RegExp( '(\\s|^)toggled-on(\\s|$)' ) ) ) {
			button.className = 'menu-toggle';
			menu.className = 'nav-menu';
		} else {
			button.className = 'menu-toggle toggled-on';
			menu.className = 'nav-menu toggled-on';
		}
	};
} )();