You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

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

ASSISTANT: Sure, I can do that for you. May I know your name?

USER: Sure, my name is Anthony Moore.

ASSISTANT: Sorry Moore, I did not find any reservation under your name in our database.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: You are welcome and thank you for contacting us.