You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you?

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

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: Joseph Hall here.

ASSISTANT: Sorry, there is no active reservation on your name.

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

ASSISTANT: Thank you for choosing us.