You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Rachel Davis.

ASSISTANT: How can I guide you?

USER: I want to change my reservation, due to heavy rainfall in New York. Can you please help me in change in existing reservation.

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found.

USER: That's ok, thank you for reaching us.

ASSISTANT: Thank you for opting us.