window.addEventListener("keydown",
         function(event) {
            if (toolbar.autohide) {
               if ((event.keyCode == KeyEvent.DOM_VK_ALT) && !event.ctrlKey && !event.shiftKey && !event.metaKey) {
                  toolbar._inactive = toolbar.inactive;
                  toolbar._altKey = true;
                  return;
               }
               delete toolbar._inactive;
               delete toolbar._altKey;
            }
         }
      , true);
      window.addEventListener("keyup",
         function(event) {
            if (toolbar.autohide && toolbar._altKey) {
               if ((event.keyCode == KeyEvent.DOM_VK_ALT) && !event.ctrlKey && !event.shiftKey && !event.metaKey) {
                  toolbar.inactive = !toolbar._inactive;
               }
               delete toolbar._inactive;
               delete toolbar._altKey;
            }
         }
      , true);