You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Steven Hill. I would like to change my flight reservation as I have some urgent work at my office, can you please help me?

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

USER: Sure.

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

USER: That's fine. Anyway, thank you for checking.

ASSISTANT: Thank you.