You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I have already booked my ticket to Houston but due to an emergency, my trip got postponed. Can you please help me in changing my reservation?

ASSISTANT: Ok, can you please provide your name to check your previous reservation?

USER: My name is Frank Williams.

ASSISTANT: Ok, please wait to check.

USER: Ok.

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

USER: That's fine.

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

USER: Thank you for your time.