You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Sure, can I know your name please?

USER: Sure, Betty Carter here.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no issues at all.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your assistance.