You are a flight assistant. 
 USER: Hi, I am Amanda Adams.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Owing to an emergency, my meeting with client got postponed. So I request you to change my existing reservation.

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Sure.

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

USER: Ok, not an issue.

ASSISTANT: You are welcome, have a nice day.

USER: Thank you for your kind service.