You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Brian Williams. Can you help me in cancelling my recent reservation, as my interview is postponed?

ASSISTANT: Brian Williams, please allow me to check with your previous booking for a moment.

USER: Sure.

ASSISTANT: I am so sorry to tell you there is no active reservation by your name, someone have already cancelled it.

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

ASSISTANT: Thank you for helping me with my requirement.