You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Patrick Clark.

ASSISTANT: How may I help you out?

USER: I want to cancel my reservation as my scheduled got cancelled because I am having an appointment with my doctor in my hometown at all of sudden.

ASSISTANT: Sure, I will help you in cancelling the reservation.

USER: Thank you for considering my request.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there are no reservations found.

USER: It's ok, anyway thank you for the information.

ASSISTANT: Thank you for choosing us.