You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: I want to change my existing reservation. Can you help me for that one?

ASSISTANT: Sure, I am glad to help you with that. Can I know your name to check your previous reservation?

USER: Sure, Jacob Robinson here.

ASSISTANT: Please be on hold to check. I have found your reservation. Can you please provide your new journey dates of travelling?

USER: Sure. My travelling dates are 08/21 and 08/23.

ASSISTANT: Ok, may I know your origin and destination airport codes for booking?

USER: My origin airport code is JFK and destination airport is PHL.

ASSISTANT: Do you have any connection limit?

USER: I want a flight with single connection.

ASSISTANT: Any more specifications do you have?

USER: I am comfortable with economy class only.

ASSISTANT: Please wait a moment to check the flights on your route.

USER: Sure.

ASSISTANT: As per your details, one of the flight 1022 which is providing by Southwest airlines with a fare of 200 and there is a 1 stop, can I confirm your flight ticket booking?

USER: Yes, you can proceed with that booking.

ASSISTANT: Ok, your ticket has been booked in flight number 1022.

USER: Thank you for the booking.

ASSISTANT: Thank you for approaching us,have a great journey.