You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am James Moore.

ASSISTANT: How may I help you?

USER: I have a sudden meeting in my office. So, I need to change my previous reservation. Can you help me out?

ASSISTANT: Sure, I will help you to change. Wait a moment.

USER: Ok.

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

USER: It's ok. Anyway, thank you for your help.

ASSISTANT: Welcome. Thank you for choosing us.