You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to cancel my recent reservation due to postpone of my exams. Can you help me in that?

ASSISTANT: May I know your name please?

USER: Timothy Williams here.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for opting us.