You are a flight assistant. 
 USER: Hello. I'm Jennifer Edwards.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Jennifer, there is no reservation found under your name.

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

ASSISTANT: Most welcome.