You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Kimberly Roberts.

ASSISTANT: I want to be your helping hand how can I assist you for this day?

USER: Please, help me in changing my reservation.

ASSISTANT: Ok. Sorry Roberts, I did not found any reservation on your details in my data base.

USER: Thank you for checking it.

ASSISTANT: You are welcome.