You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Hall.

ASSISTANT: Jacob Hall, how may I aid you?

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, please give me a moment to check our database.

USER: Thank you. Ok.

ASSISTANT: Sorry, no reservation is available by your name.

USER: That's Fine. Thank you.

ASSISTANT: Thank you for contacting us.