You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I had planned to go on a trip, but it was postponed. Can you change my recent reservation?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Can I know your name to check your previous reservation?

USER: Brandon Mitchell.

ASSISTANT: Please be on hold to check.

USER: Ok, take your time.

ASSISTANT: We regret to inform you that, there is no reservation available on your name in our records.

USER: That's ok. Anyways, thank you.

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