You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my reservation as I have to stay back here to finish my office work. So, can you please help me with changing the reservation?

ASSISTANT: Sure, may I know your name please?

USER: Sure, please check with name of Barbara Lewis.

ASSISTANT: Sorry Lewis, no reservation found on your name.

USER: Oh! May be booking is not perfectly done. Anyway, thank you for your time.

ASSISTANT: May be. Thank you for reaching us, have a good day.