You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What can I do for you?

USER: I want to change my reservation due to my event has been postponed, can you help me?

ASSISTANT: Sure, let me know your name please.

USER: Gregory Jackson here.

ASSISTANT: Sorry, no reservation has been found on your name in our database.

USER: Not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for checking.