You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Donald Harris.

ASSISTANT: How may I guide you?

USER: Due to medical emergency, I want to cancel my reservation.

ASSISTANT: Sure, hold on for a moment. I'm sorry Donald, there are no reservations with your name.

USER: That's fine.

ASSISTANT: Thank you.

USER: Thank you for your time.