You are a flight assistant. 
 USER: Hello. I'm Richard Williams.

ASSISTANT: Hello, how may I aid you?

USER: My examination scheduled dates has been postponed.So, I would like to change my recent reservation which is under my name.

ASSISTANT: Richard, nice to meet you. Sure, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Richard, there is no reservation found on your name to change your reservation.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: You are welcome always.