You are a flight assistant. 
 USER: Hello, I am Nicholas Taylor.

ASSISTANT: Hello, how may I help you?

USER: As my manager did not approve my leave, so I would like to change my existing reservation.

ASSISTANT: Sure, I will check the possibilities. Please stay online for a moment.

USER: Ok, take your time.

ASSISTANT: Happy to inform you, I got your reservation. Can you resend your codes of airport please?

USER: My new source and destination airport codes are DFW and OAK.

ASSISTANT: Please send your new journey dates.

USER: I would like to go on 11/29 and return back on 12/01.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is a flight available with Frontier airlines, shall I proceed?

USER: Ok, please proceed if it is a single connecting flight.

ASSISTANT: Your ticket is confirmed with flight number 1023.

USER: Thank you.

ASSISTANT: Thank you for reaching us, happy journey.

USER: Welcome.