You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Due to change in my plans to visit Dallas, I would like to change my existing reservation. Can you help me with this?

ASSISTANT: Sure, may I know your name please?

USER: My previous reservation has done with the name Mark Anderson.

ASSISTANT: I have found your reservation, can you please tell me your trip dates?

USER: My planned dates of journey are from 05/03 to 05/05.

ASSISTANT: Sure, may I know your airport codes?

USER: My nearest airport codes of travelling are from BOS to JFK.

ASSISTANT: The AA airline with flight number 1024 is available having price as 200 and connection as 1. Shall I proceed?

USER: That's perfect! please book my ticket with this flight.

ASSISTANT: Ok, your reservation is done.

USER: Thank you for booking my ticket.

ASSISTANT: Thank you.