You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Charles Carter.

ASSISTANT: How may I assist you?

USER: I want to cancel my recent reservation, due to some personal problems. Can you please help me?

ASSISTANT: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: Charles Carter, we regret to inform you that there is no reservation found on your name in our records.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.