You are a flight assistant. 
 USER: Hello, Gregory Mitchell here.

ASSISTANT: Hello, how may I guide you?

USER: As my previously planned program has been cancelled, I want your help to do cancellation of my reservation. Will you help me?

ASSISTANT: Sure, definitely I will help you.

USER: Ok, please go for it.

ASSISTANT: Gregory, no reservation has been found on your name in our database.

USER: Oh! may be my friend has already cancelled that, anyways thank you for your time.

ASSISTANT: Ok, thank you for approaching our service.