public UserVO login(String username, String password) {
		UserVO user = null;
		try {
			connection = DriverManager.getConnection(URL, USER, PASSWORD);
			Statement statement = connection.createStatement();
			System.out.println("SELECT * FROM user WHERE username = '"+username+"';");
			ResultSet result_user = statement.executeQuery("SELECT * FROM user WHERE username = '"+username+"';");
			if (result_user.next()) {
				user = new UserVO();
				user.setUsername(result_user.getString("username"));
				System.out.println("SELECT * FROM user WHERE username = '"+username+"' AND password = '"+password+"';");
				ResultSet result_password = statement.executeQuery("SELECT * FROM user WHERE username = '"+username+"' AND password = '"+password+"';");
				if (result_password.next()) {
					user.setLastLoginDate(result_password.getString("lastLoginDate"));
					user.setRole(result_password.getString("role"));
					user.setMessage(result_password.getString("message"));
					user.setPassword(result_password.getString("password"));
					setLastLoginDate(statement, user.getUsername());
				}
				result_password.close();
			}
			result_user.close();
			statement.close();
		} catch (Exception e) {
			Logger.getInstance().logError(new StringBuffer("Es konnte keine Verbindung zur Datenbank aufgebaut werden."));
			System.out.println("Failed to send sql query.");
			e.printStackTrace();
		} finally {
			if (connection != null) {
				try { 
					connection.close(); 
				} catch(Exception e) {
					Logger.getInstance().logError(new StringBuffer("Die Verbindung zur Datenbank konnte nicht geschlossen werden."));
					System.out.println("Failed to close connection.");
					e.printStackTrace(); 
				}
			}
		}
		return user;
	}