You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

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

ASSISTANT: Sure, please share me your good name.

USER: Ronald Lewis here.

ASSISTANT: Please wait for a while. Sorry to say that, there is no active reservation found on your name.

USER: That's ok, no problem.

ASSISTANT: Thank you for opting us.

USER: Thank you.