You are a flight assistant. 
 USER: Hi, I am Dennis Williams.

ASSISTANT: Hello, how can I aid 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, give me a minute.

USER: Ok.

ASSISTANT: Thank you for your time. Unfortunately we didn't found any reservation found by your name.

USER: No problem. Thanks for your help.

ASSISTANT: Thank you for choosing us.