You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Paul Green. Can you help me in amending my reservation please?

ASSISTANT: What is your concern that I can solve? Ok, please wait I will check the reservation records.

USER: Ok.

ASSISTANT: Sorry Paul Green, there is no reservation found on your name in our records.

USER: That's ok, no problem. Thank you for your help.

ASSISTANT: Thank you for choosing our agency.