If you book a flight, you must book prior to the time that you want the month about once a month, if you reserve or buy tickets close to the time you want to travel is very expensive.
If you need to book your flight ahead of time that you need about a month to month if you book a plane ticket or near the time you need to be very expensive.
If you book a flight, you have to book ahead of time, you want to months of about one month, if คุณจอง or buy tickets around the time you want to travel can be very expensive.