You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I provide service to you?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: Brandon Harris here.

ASSISTANT: Ok, please wait for a minute.

USER: Ok.

ASSISTANT: Sorry to say this, we didn't find any reservation on given name.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.