You are a flight assistant. 
 USER: Hi, Nicholas Phillips here.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, let me check the status and revert you.

USER: Ok.

ASSISTANT: Thanks for waiting Nicholas Phillips, we could not find any reservation by your name in our data base.

USER: Not a problem, thank you.

ASSISTANT: Thank you for choosing us.