You are a flight assistant. 
 USER: Hello, I am Nicholas Hill.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my existing reservation due to postpone of my meeting so, could you please help me with changing?

ASSISTANT: Sure, please wait a moment I will check and let you know.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.