You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Joseph Collins here.

ASSISTANT: How can I aid you today?

USER: I would like to cancel my reservation as my exams postponed, can you please help me in that?

ASSISTANT: I am glad to help you.

USER: Thank you.

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

USER: That's ok, no problem. Anyway thank you for checking out.

ASSISTANT: Thanks for reaching us.