You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What kind of assistance are you looking for?

USER:  I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you please help me in changing my reservation?

ASSISTANT: Sure, please let me know your name to check the reservation list.

USER: Benjamin Parker.

ASSISTANT: Ok, give me sometime.

USER: Ok.

ASSISTANT: Thank you for waiting, Sorry there is no active reservation have been found under your name in our database to change it.

USER: No issue. Thank you for the information.

ASSISTANT: Thank you for approaching us.