You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Due to change in the meeting venue, I would like to change my existing reservation. Help me in doing so.

ASSISTANT: Sure, may I know your name for changing existing reservation?

USER: My name is Joseph White.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: No reservation found on your name Joseph White. Would you want to know anything else?

USER: That's fine. No, thanks .

ASSISTANT: Thank you for contacting us.

USER: You are welcome.