You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I want to cancel my reservation due to health issues, can you please help me with this?

ASSISTANT: Sure, may I know your name?

USER: I am William Clark.

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

USER: It's ok, thank you.

ASSISTANT: Thank you.