You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Paul Brown here.

ASSISTANT: How can I assist you?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please be on hold.

USER: Ok.

ASSISTANT: There is no reservation found under your name in our records, Paul.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for choosing us.