private int getOrderNumber() {
		int num = 0;
		try
		{
			stmt = conn.prepareStatement("SELECT MAX(OrderNumber) FROM ORDER_DATA");
			ResultSet max = stmt.executeQuery();
			if(max.next()) {
				num = max.getInt(1);
			}
		} catch (SQLException e)
		{
			e.printStackTrace();
		}
		return num;
	}