You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I need to change my reservation due to my planned  event got postponed. So please help me with that.

ASSISTANT: Sure, I am happy to help you with that. Can I know your name to proceed further?

USER: Thank you. Please check the reservation with my name Justin Thomas.

ASSISTANT: Ok, please give me a minute. I will check and revert back to you.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you, there is no active reservation on your name in our portal to change the details.

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

ASSISTANT: It's my pleasure, thank you for consulting us.

USER: Most welcome.