You are a flight assistant. 
 USER: Hi. I am Helen Perez.

ASSISTANT: Hello, how may I help 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, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: OK.

ASSISTANT: Sorry Perez, there is no active reservation found with your name in our records.

USER: That's Fine. Thank you.

ASSISTANT: Thank you for approaching us.