You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Frank Moore.

ASSISTANT: how may I render you?

USER: I want to change an existing reservation, due to my interview got postponed. So please help me in changing the reservation.

ASSISTANT: Sure, I can help you with it. Please hold on.

USER: Sure.

ASSISTANT: Thanks for your time. There was no reservation found on your name.

USER: Not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you.