You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you for considering my request.

ASSISTANT: Can you share your name to check further?

USER: Sure, myself Brian Taylor.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, no reservation found on your name in our records to change it.

USER: That's ok, no problem, anyway thank you for the information.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your service.