You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Yes, I am here to help you. May I know your name please?

USER: I am Joshua Collins.

ASSISTANT: Ok, please wait a minute I will get back to you.

USER: Sure.

ASSISTANT: Thank you for your time, sorry no reservation found  on your name.

USER: Ok, no problem.

ASSISTANT:     Thank you for reaching us, have a good day.

USER: Thank you for your information.