You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Carol Baker, I would like to change my reservation which I have done last week. Can you please help me about it?

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Ok, please take your time.

ASSISTANT: Sorry, there is no reservation found on your name. Thank you for choosing us, have a nice day.

USER: Ok, fine. Thank you for the information.