You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, We are here to help you. May I know your name?

USER: Thank you for considering my request. Myself Carolyn Roberts.

ASSISTANT: Give me a minute.

USER: Sure, take your own time.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Not an issue, anyway thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.