You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you now?

USER: My name is Charles Miller.

ASSISTANT: Thanks for providing your name.

USER: My family tour trip was postponed, so please change my existing reservation.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry there is no reservation found on your name.

USER: No problem, Thanks for your service.

ASSISTANT: Thanks for connecting with us. Wish you a great day.