You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My name is Daniel Robinson. I would like to change my existing reservation, could you help me out?

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Thanks for your time, there is no flight reserved with your name to change it.

USER: That's ok.

ASSISTANT: Thanks for contacting us.

USER: Thank you for your time.