window.onload = function() {

	var menuID = 'navigation'; // The ID of your menu
	var activeClass = 'active'; // The class to add

	var menu = document.getElementById(menuID);
	var items = menu.getElementsByTagName('a');
	for( var i = 0; i < items.length; i++ ) {
		if( items[i].href.replace(/https?:\/\/.*?\//i , '/') ==
			location.href.replace(/https?:\/\/.*?\//i , '/') ) {
			items[i].parentNode.className = activeClass;
			break;
		}
	}

};