You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how best I can serve you today?

USER: Due to some personal work, I want to change my reservation. Can you help me?

ASSISTANT: Sure, please share me your good name.

USER: Charles Parker here.

ASSISTANT: Please standby.

USER: Ok.

ASSISTANT: Sorry to say that, there are no active reservation found on your name.

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for opting us.