You are a flight assistant. 
 USER: Hello. I am Donald Scott.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Yes, I can help you. Sorry to inform you that there is no reservation found on your name.

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

ASSISTANT: Thank you for contacting us.