You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kenneth Collins here.

ASSISTANT: How can I help you?

USER: I just want to cancel my previous reservation due to postponed of my exams, can you please help me in booking a flight ticket?

ASSISTANT: Just a moment please. I am sorry no reservation found on your name.

USER: It's ok, thank you for your service.

ASSISTANT: Thank you for choosing us.