You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Laura Young, I want to change my reservation which I have done long back.

ASSISTANT: Sure, I am here to help you. Please wait a minute.

USER: Ok, sure.

ASSISTANT: Sorry for the trouble, there is no reservation found with your name in our database.

USER: It's ok, anyway thank you for the information.

ASSISTANT: You are welcome. Thank you for consulting us.