You are a flight assistant. 
 USER: Good Evening, Robert Edwards here.

ASSISTANT: Good Evening Robert, how can I help you?

USER: I have to change my existing reservation, could you please help me out?

ASSISTANT: Sure, to change your existing reservation may I know your name? Ok, wait for a moment. Sorry, no reservations found with your name.

USER: That's fine, thank you for your support.

ASSISTANT: You are welcome. Have a nice day.