You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donald Barker.

ASSISTANT: How can I help you today?

USER: I want to change my reservation, help me in changing my reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thanks.

ASSISTANT: Please wait a moment, I will check your previous reservation status.

USER: Ok.

ASSISTANT: There is no previous reservation available on your name.

USER: That's ok, might be my father has changed. Anyway, thank you for your help.

ASSISTANT: Thank you for reaching us, have a nice day.