You are a flight assistant. 
 USER: Hello. Myself Carolyn Mitchell.

ASSISTANT: Hello, how may I guide you?

USER: I want to change my existing reservation, can you help me for that?

ASSISTANT: Sure, hold on for a moment.

USER: Ok.

ASSISTANT: I'm sorry, there are no reservations with your name.

USER: Ok, that's fine. Thank you for your services.

ASSISTANT: Thank you, have a good day.