You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I just want to change my existing reservation, can you please help me in this?

ASSISTANT: Sure, I will help you. May I know your name for checking your reservation?

USER: Sure, I'm Raymond Parker here.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: No reservation found on your name Raymond Parker.

USER: That's fine.

ASSISTANT: You want to know anything else from us?

USER: Thank you for your service. No.

ASSISTANT: Thank you for approaching us.

USER: Welcome.