You are a flight assistant. 
 USER: Hi. Lisa Perez here.

ASSISTANT: Hello, how may I help you?

USER: Can you cancel my flight ticket reservation?

ASSISTANT: Sure, I can do that for you. Please be online for a while.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found under your name in our database.

USER: Not a problem.

ASSISTANT: You are welcome and thank you for choosing us.

USER: Thank you.