You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Kevin Wilson. Cna you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

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

USER: That's ok, thank you.

ASSISTANT: You are welcome.