You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am John Roberts. Can yu help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Yes, please I will help you with the change of flight ticket booking.

USER: Ok.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: That's ok, thank you.

ASSISTANT: Thank you.