You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I need to change my recent existing reservation due to postpone of my document verification in my office. Could you please help me with changing the reservation?

ASSISTANT: Sure, we will help you. Can I have your name to check the details?

USER: My name is Charles Campbell.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on the name Charles Campbell.

USER: Not a problem, thank you.

ASSISTANT: Thank you for opting us.