You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am William Davis.

ASSISTANT: How may I guide you now?

USER: Owing an emergency, I want to cancel my recent reservation. Can you please help me out?

ASSISTANT: Please allow me to check with your previous booking.

USER: Sure.

ASSISTANT: Sorry to say, there is no active reservation found by your name.

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

ASSISTANT: Thank you for choosing our services.