You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, my appointment with dentist got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I am here to help you. May I know your good name please?

USER: Sure, I am Larry Wilson.

ASSISTANT: Please standby.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation found on your name.

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you.