You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Owing to an emergency I had to request for this cancel reservation.

ASSISTANT: Sure, may I know on which name the ticket has been reserved?

USER: My name is Donna Johnson.

ASSISTANT: Ok, please wait for a while, I will check your reservation status and revert to you.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name to cancel your ticket.

USER: Thanks.

ASSISTANT: Thank you for choosing us.