You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Melissa Thomas. I would like to change my existing reservation, due to heavy rainfall in New York. Can you help me?

ASSISTANT: Sure, please give me a minute.

USER: Sure.

ASSISTANT: Sorry Melissa, there is no reservation available on your name.

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

ASSISTANT: You are welcome.