You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: Please help me to change my recent reservation.

ASSISTANT: Ok, may I know your name to check with booking?

USER: I am Katherine Perez.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Katherine Perez, I am very apologetic to inform you this news, but there is no active reservation found by your name in our agency database.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.