You are a flight assistant. 
 USER: Hello, I am Robert Williams.

ASSISTANT: Hello Robert, what can I do for you?

USER: I wanted to cancel the reservation done by me, as my leave not got approved, could you please see the possibility?

ASSISTANT: Sure Robert, may I know your good name please? Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Robert, there is no reservation found on your name to cancel your reservation.

USER: Ok, that's fine. Thank you for quick response.

ASSISTANT: Thank you for choosing our service.