You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Owing an emergency, I want to cancel my reservation. Can you help me for that?

ASSISTANT: Please let me know your name?

USER: My name is Joseph Walker.

ASSISTANT: Sorry, there is no reservation by your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.