public Timestamp getNoteUpdateTime(int noteId) throws SQLException {
		NoteDatabaseManager dm = new NoteDatabaseManager();
		String s_noteId = Integer.toString(noteId);
		String sql = "select update_time from note where note_id = "
				+ s_noteId + ";";
		ResultSet rs = dm.sqlQuery(sql);
		
		Timestamp noteUpdateTime = null;
		while (rs.next()) {
			noteUpdateTime = rs.getTimestamp("update_time");
		}
		return noteUpdateTime;
	}