You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: As my meeting got cancelled in Dallas, So I would like to cancel my recent reservation to Dallas.

ASSISTANT: May I know your name to check for the previous reservation?

USER: Previously, I have booked my ticket with the name of Karen Smith.

ASSISTANT: Please allow me a moment to check for previous reservation.

USER: Sure.

ASSISTANT: Karen, there is no reservation found under your name.

USER: May be my friend has cancelled my reservation on behalf of me.

ASSISTANT: Ok, thank you for contacting us.

USER: Anyway, thanks for checking.