You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: David Walker here, I want to cancel my reservation due to my schedule got cancelled.

ASSISTANT: Just a second please.

USER: Ok, sure take your time.

ASSISTANT: I am sorry no reservation found on your name.

USER: It might not be done properly at the time of booking. Anyway thank you for the information.

ASSISTANT: Thank you for choosing us.

USER: You are welcome.