(function (window, document) {

var layout   = document.getElementById('layout'),
menu     = document.getElementById('menu'),
menuLink = document.getElementById('menuLink');

function toggleClass(element, className) {
  var classes = element.className.split(/\s+/),
  length = classes.length,
  i = 0;

  for(; i < length; i++) {
    if (classes[i] === className) {
      classes.splice(i, 1);
      break;
    }
  }

  // The className is not found
  if (length === classes.length) {
    classes.push(className);
  }

  element.className = classes.join(' ');
}

menuLink.onclick = function (e) {
  var active = 'active';

  e.preventDefault();
  toggleClass(layout, active);
  toggleClass(menu, active);
  toggleClass(menuLink, active);
};

}(this, this.document));