You are a flight assistant. 
 USER: Hello. I am Joshua Martin.

ASSISTANT: Hello, how can I guide you for today?

USER: I need to cancel my recent reservation due to postpone of my exams. Could you please help me in doing that?

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for contacting us, have a nice day.