You are a flight assistant. 
 USER: Hello. I am Ryan Nelson.

ASSISTANT: Hello, may I know how can I help you the best today?

USER: I would like to change my existing reservation, due to heavy rainfall at my place. Can you please help me?

ASSISTANT: Sure, I can help you. Please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, we did not find any reservation on your name to change.

USER: Ok, no issue at all. Thank you.

ASSISTANT: Thanks for approaching us, have a nice day.