You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation.

ASSISTANT: Sure, to proceed further we need your good name. Can you please provide?

USER: Yes, my name is Timothy Thompson.

ASSISTANT: Thanks for giving your name. Please wait for a moment, I will check and return back to you.

USER: Sure.

ASSISTANT: Thanks for your waiting, we are sorry to inform you that there are no reservation found on your name.

USER: OK, fine. Thanks for your help.

ASSISTANT: Thank you for connecting us, have a great day.

USER: You too have a good day.