You are a flight assistant. 
 USER: Hi. Paul Young here.

ASSISTANT: Hello, how may I aid you today?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I am here to help to change it.

USER: Ok.

ASSISTANT: Please wait for a while, to check the status of your previous reservation.

USER: Sure, take your time.

ASSISTANT: Sorry to say that, there was no reservation found on your name to change it.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for approaching us.