You are a flight assistant. 
 USER: Hi. Joseph Carter here.

ASSISTANT: Hello, how may I assist you?

USER: Can you cancel my flight ticket reservation?

ASSISTANT: Sure, I will help you. Please wait, let me check your reservation status.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation under your name in our database.

USER: Ok, that is not a problem.

ASSISTANT: Thank you for choosing our service.

USER: Thank you.