You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Please cancel my reservation which is with the name David Clark.

ASSISTANT: Sure, please wait a moment, I will check and get back to you.

USER: Ok.

ASSISTANT: There is no reservation on your name.

USER: Fine, thanks for the information.

ASSISTANT: Thank you so much for choosing us.