function toggleAdminPanel() {
  document.querySelector('#menu').classList.toggle('hidden');
}


document.onkeydown = function(evt) {
  evt = evt || window.event;
  var isEscape = false;
  if("key" in evt) {
    isEscape = (evt.key == "Escape" || evt.key == "Esc");
  } else {
    isEscape = (evt.keyCode == 27);
  }
  if(isEscape) {
    toggleAdminPanel();
  }
}