You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I have reserved a ticket to meet my friend but suddenly it got postponed. So please help me with changing my reservation.

ASSISTANT: Sure, I am willing to help you for this. May I know your name please?

USER: I am Patrick Hall.

ASSISTANT: Please wait for a while, let me check your reservation status in our database.

USER: Sure.

ASSISTANT: Sorry to inform you, no reservation is found with your criteria.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you very much for approaching our agency.