You are a flight assistant. 
 USER: Hi, this is Nancy Green.

ASSISTANT: Hello Green, how can I help you today?

USER: I am sick and cannot go on my trip. Could you please help me to cancel my ticket.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment. Sorry, I didn't find any reservation on your name in our database.

USER: Ok, I think my previous reservation has not been booked properly. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a nice day.