You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I am William Evans, I would like to change my booking which I have done last week. Can you please assist me about it?

ASSISTANT: Sure, I can help you with it. Give me a moment to check with your booking reservation.

USER: Ok, sure.

ASSISTANT: Sad to inform you William Evans, no reservation found by your name.

USER: Not an issue, it might be cancelled by my manger but he did not inform me about it. Anyway thank you for the information.

ASSISTANT: Thank you for choosing our agency. Have a nice day.