You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Elizabeth Walker.

ASSISTANT: How may I assist you at this moment?

USER: My planned trip got cancelled due to some reasons, can you please help me in cancelling the ticket?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

ASSISTANT: Please wait a moment to check your previous reservation.

USER: Sure, take your time.

ASSISTANT: We regret that, there is no reservation with your name in our records.

USER: That's fine, thanks a lot for checking.

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

USER: You are welcome.