You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I had reserved a flight in the past week for a weekend trip but suddenly the trip got cancelled due to an exam in our college, I would like to cancel my ticket. Can you please help me?

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: May I know your name?

USER: I am Mark Walker.

ASSISTANT: Sorry mark, there is no reservation found basis on your details.

USER: ok, no problem, I think my brother might cancelled my ticket. Thank you for you help.

ASSISTANT: Thank you for reaching us.