You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I support you today?

USER: Owing to an emergency, my planned trip to Yosemite adventure has been cancelled. So I want you to cancel my existing reservation.

ASSISTANT: Sure, we are here to help you with cancellation. May I know your name?

USER: Sure, I have a recent reservation with name Lisa Evans.

ASSISTANT: Sure, please be on hold.

USER: Sure.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: Ok, no worries at all. Thank you for your support.

ASSISTANT: Thank you for choosing our service.