You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Margaret Johnson.

ASSISTANT: How may I assist you today?

USER: Owing to an emergency, my meeting with client has been cancelled. So I request you to cancel my existing reservation.

ASSISTANT: Sure, I will assist you with that. Please wait a moment to check your previous reservation.

USER: Sure.

ASSISTANT: We regret to inform you that, there is no reservation on your name in our records.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us, hope you have a great day.

USER: Thank you for your assistance.

ASSISTANT: Welcome.