You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Christopher Adams.

ASSISTANT: How may I aid you today?

USER: My business meeting has been postponed. So, I would like to change my reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you with that. Please wait for a while.

USER: Sure, take your time.

ASSISTANT: I am sorry to say that there is no reservation found.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you.

USER: You are welcome.