You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you today?

USER: Help me in cancelling my reservation?

ASSISTANT: Sure, I will help you with that. Please provide your name to check your previous reservation.

USER: I am Sarah Hill.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: We regret to inform you that, there is no reservation found on your name in our reservation list.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.