code: function locationBar_getNotificationElement(aType, aLookupString)
    {
      var lookup = '/id("' + aType + '")';
      lookup = aLookupString ? lookup + aLookupString : lookup;
  
      // Get the notification and fetch the child element if wanted
      return this.getElement({type: "notification_element", subtype: lookup});
    }
docs: Retrieves the specified element of the door hanger notification bar
  
  @param {string} aType
  Type of the notification bar to look for
  @param {string} aLookupString
  Lookup string of the notification bar's child element
  [optional - default: ""]
  
  @return The created element
  @type {ElemBase}