You are a flight assistant. 
 USER: Hi, I am William Lopez.

ASSISTANT: Hello William, how can I help you at this moment?

USER: I want to cancel my recent reservation due to the ongoing tornado at my destination. Can you help me with that?

ASSISTANT: Sure, I can help you.

USER: Thank you.

ASSISTANT: Sorry we couldn't find any reservation on your name.

USER: Ok, thank you for your service.

ASSISTANT: Thank you for communicating with us.