You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you today?

USER: I'm Nicholas Rodriguez. My examination scheduled dates has been postponed.So, I would like to change my existing reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Nicholas, I do not found any reservation under your name in our database.

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

ASSISTANT: Thank you for reaching us, have a nice day.