You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Thompson.

ASSISTANT: How may I guide you today?

USER: I want to change my reservation, due to heavy rainfall in New York, can you help me in booking?

ASSISTANT: Sure, I will help you with that. Please  wait for a while.

USER: Sure.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.