public void update(String Username,ModelMap model){
		
		System.out.println("entra a update....");
		DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
		Query query = new Query("Usuario");
		query.addFilter("Username", FilterOperator.EQUAL, Username);
		PreparedQuery pq = datastore.prepare(query);
		Entity e = pq.asSingleEntity();
		model.addAttribute("Usuario",  e);
		
	}