You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am Rebecca Hill. I would like to re modify an existing reservation which has been booked earlier this week.

ASSISTANT: Ok Rebecca, could you please give me a moment to check?

USER: Please take your best time.

ASSISTANT: Thank you for your patience. Sorry to tell you that, there is no reservation available on your name.

USER: Ok, thank you for the information.

ASSISTANT: You are welcome.