You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Mark White.

ASSISTANT: Nice to meet you Mark.

USER: I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Thank you for waiting, Could you please share your preferable airport codes?

USER: CLT and DTW are my  preferable airport codes.

ASSISTANT:  Mark , may I know your planned travel dates for booking your ticket?

USER: 08/30 and 09/01 are my travelling dates.

ASSISTANT: There is a connecting flight in Spirit airline with a fare of 300. Shall I proceed with booking?

USER: You can reserve it.

ASSISTANT:  Mark, your booking  is confirmed with flight number 1029.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us, have a safe journey.