You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Brain Hall.

ASSISTANT: How can I help you?

USER: As my appointment with doctor got cancelled I want to cancel my reservation. Can you help me with it please?

ASSISTANT: Brain Hall, please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Brain Hall, I am very sorry to inform you that there is no reservation by your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you for choosing us.