You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Could you help me in changing my recent reservation?

ASSISTANT: May I know your name please?

USER: I am Sarah Hill.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.