You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to cancel my reservation, because of sudden change in my trip.

ASSISTANT: Sure, to cancel may I know your name?

USER: My name is Angela Roberts.

ASSISTANT: Roberts, no reservations found with your name.

USER: That's fine, thanks for helping me.

ASSISTANT: Thank you for contacting us.