You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: My trip was cancel, due to I have exams on those dates so I am unable to travel those dates so can you please cancel my reservation?

ASSISTANT: Sure, I am glad to help you.

USER: Thanks.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: Sure, my name is Kevin Hernandez.

ASSISTANT: Ok, please be on hold.

USER: Ok.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: Oh! May be my friends already cancelled my ticket.

ASSISTANT: Thank you for approaching us, have a great day.

USER: Thank you for your service.

ASSISTANT: Welcome.