You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I would like to change my existing reservation.

ASSISTANT: Sure, could you please provide me your details?

USER: Yes, I am Rachel Miller.

ASSISTANT: Thank you for giving your name, may I know your journey place and dates? please wait a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation on your name.

USER: OK, thank you.

ASSISTANT: Have a nice day.