You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donald Collins.

ASSISTANT: How can I aid you at this moment?

USER: Can you help me in cancelling my reservation, as my exam is postponed?

ASSISTANT: Sure, I will help you in cancelling your reservation.

USER: Ok.

ASSISTANT: Please give me a moment to check your reservation status. Donald Collins, there is no active reservation found under your name in our database.

USER: That's ok, thank you.

ASSISTANT: Thank you for contacting us.