You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you at this moment?

USER: In the last month I have reserved a flight on my name to travel to Las Vegas to celebrate my father birthday but suddenly there is an examination on the same date our college management has informed suddenly to us. So I will travel to my home on some other dates. Can you please help me in changing my flight ticket booking?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: My name is Rachel Baker.

ASSISTANT: Please be on hold to check.

USER: Sure.

ASSISTANT: Sorry to inform you that, there is no reservation with your name in our records.

USER: Ok, not a problem with that one. Thank you for your information.

ASSISTANT: Thank you for approaching us, have a great day.

USER: Welcome.