private boolean open() {
		boolean result = false;
		if (!isValid()) {
			try {
				Class.forName("com.mysql.jdbc.Driver");
				this.connection = DriverManager.getConnection(this.url, this.user, this.password);
				if (isValid()) 
					if (isDBExisted() || createDB())
						if (isTableExisted() || createTable()) 
							result = true;
						else 
							System.err.println("Table failed.");
					else
						System.err.println("Database failed.");
				else
					System.err.println("Connection Failed.");
			}
			catch (Exception e) {
				System.err.println(e.toString());
			}
		}
		return result;
	}