You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to modify my reservation, can you help me out?

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

USER: Myself Patricia Hall.

ASSISTANT: Sorry Hall, no reservation found with your name to change the reservation.

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

ASSISTANT: Thank you for opting us.

USER: Welcome.