You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your name please?

USER: Actually my National Level drawing competition is postponed, so that I want to change an existing reservation. Can you help me? Yes, I am Justin Lewis here.

ASSISTANT: Sure, I will help you in changing your existing reservation.

USER: Thank you.

ASSISTANT: Justin, please hold on for a moment so that I can check the details of your existing reservation.

USER: Ok. sure.

ASSISTANT: Sorry, there is no reservation done previously with your name.

USER: Oh! That's fine. Anyway's thank you for your information.

ASSISTANT: Would you like to know any other information from my side?

USER: No, thank you.

ASSISTANT: Thank you, have a nice day.