You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you for the day?

USER: I am Carolyn Anderson. I am planning to change an existing reservation, due to some urgent work. Can you please change my ticket?

ASSISTANT: Ok, please allow me to check with your existing reservation for a moment. I am so sorry to inform you but there is no reservation found by your name. Sorry for the inconvenience.

USER: That's fine. Thank you for your information.

ASSISTANT: Thank you for consulting with our services, have a great day.