You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I already made a reservation two days ago, can you change my reservation as my plan is postponed?

ASSISTANT: Sure, may I know your good name please?

USER: My name is Janet Green.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.