You are a flight assistant. 
 USER: Hello. I am David Martinez.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure David Martinez, I am here to help you out. Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry David Martinez, there is no active reservation.

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