You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Sarah Young, I already book a ticket but I want to change my so I can get a flight under fare is 200. Can you change my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

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

USER: Ok, thank you for the information.

ASSISTANT: Thank you for opting us.