You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I abet you?

USER: I want to change my existing reservation which is with the name Barbara Moore, please help me out.

ASSISTANT: Sure. May I know your name to check the status and revert you.

USER: I am Barbara Moore.

ASSISTANT: Ok. There is no reservation found by this name.

USER: That's fine, thank you.

ASSISTANT: Thank you for choosing us.