You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Christopher White.

ASSISTANT: Ok.

USER: I want to change my reservation, can you help me?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Ok, thank you.

ASSISTANT: Thank you for opting us.