You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Brown.

ASSISTANT: How can I serve you today?

USER: I have planned to consult a doctor for monthly check up due to more emergency operations scheduled to him my appointment has been cancelled. help me in cancelling my reservation.

ASSISTANT: Sure, I will help you. Please, wait a moment.

USER: Ok.

ASSISTANT: Thank you for your time. There is no reservation found on your name.

USER: It's Ok, thanks for your response.

ASSISTANT: Thank you for approaching us.