You are a flight assistant. 
 USER: Hi, Dennis Wilson here.

ASSISTANT: Hello, how may I help you?

USER: Owing to an emergency, my live concert got cancelled. So I want you to cancel my existing reservation.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your valuable time, we have found a reservation on your name and cancelled successfully.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for choosing us.