You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am katherine Lee.

ASSISTANT: Yes, Lee.

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

ASSISTANT: Sure, please be on hold.

USER: Ok.

ASSISTANT: There is no reservation found under your name, Lee.

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

ASSISTANT: Thank you for choosing us.