public static Cliente login(String login, String senha) {

	    	Cliente cliente = null;


	    	 Session session = DAO.getSessionFactory().openSession();
	    	 Transaction tr = null;

	         try {

	             tr = session.beginTransaction();
	             String queryString = "from Cliente WHERE login = '" + login + "' AND senha = '" + senha + "'";
	             Query query = session.createQuery(queryString);

	             cliente = (Cliente) query.uniqueResult();

	         } catch (RuntimeException e) {

	             e.printStackTrace();

	         } finally {

	             session.flush();
	             session.close();
	         }
	         return cliente;
	     }