You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your good name please?

USER: I'm David Brown.

ASSISTANT: OK David, how can I assist you for today?

USER: I had recently planned for a vacation.but, it was postponed due to some personal reasons.could you please help me in cancelling my reservation?

ASSISTANT: Sure David, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name.

USER: That's OK. Anyways, thank you for your help.

ASSISTANT: Thank you for approaching us. Have a great day.