You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I need to change my reservation as my planned event got postponed so please help me with changing my reservation.

ASSISTANT: I will guide you on this, please let me know your name on which the reservation is done.

USER: Sure, myself Lisa Thomas.

ASSISTANT: Sorry Lisa Thomas, there is no reservation been found on your name. Sorry for the inconveniences.

USER: Oh! It may not be booked properly while booking. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing our agency.

USER: Most welcome.