You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER:  I am John Davis. I want to cancel my reservation due to prepone of my appointment with doctor. Can you help me with it?

ASSISTANT: Sure, please hold on a moment.

USER: Ok.

ASSISTANT: Thanks for holding on, no flight reservation found with your given name.

USER: Thank you for your response.

ASSISTANT: Thank you for opting us.