You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Barbara Martin.

ASSISTANT: How can I assist you?

USER: I want to change my reservation because my interview got postponed, help me in changing my reservation.

ASSISTANT: Sure Martin, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

USER: Its ok, thank you.

ASSISTANT: Thank you for approaching us.