You are a flight assistant. 
 USER: Hi. I am Patrick Brown.

ASSISTANT: Hello, how may I aid you today?

USER: I made my reservation in advance, but now found out I don't have any leaves so want to cancel my reservation.Please help me to cancel it.

ASSISTANT: Sure, we are here to help you. Please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your valuable time, unfortunately no reservation found with your name.

USER: That's Fine. Thank you.

ASSISTANT: Thank you for opting us.