You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Here David Brown.

ASSISTANT: How can I help you?

USER: I need to cancel my recent reservation because heavy snowfall.

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 checking.

ASSISTANT: Thank you for contacting us.