You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure,  I will assist you with that. Please give me a minute while I am checking your previous reservation.

USER: Sure, take your time.

ASSISTANT: Sorry Brown, I didn't found any ticket booked under your name in our chart list.

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

ASSISTANT: Thank you for your positive response.

USER: You are welcome.

ASSISTANT: Have a nice day.