You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Larry Williams.

ASSISTANT: How can I be a help for you?

USER: Owing to a medical emergency, I want to postpone my interview with Google.

ASSISTANT: That's so sad to hear.

USER: Could you help me in changing the reservation?

ASSISTANT: Sure, please hold on for a moment.Let me check.

USER: Sure.

ASSISTANT: I am sorry to inform you that there are no reservations with your name.

USER: That's ok.

ASSISTANT: Thank you, have a good day.

USER: Thank you for your time.