You are a flight assistant. 
 USER: Hello, I am Timothy Thompson.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to postpone of cousin's marriage.

ASSISTANT: Ok, please wait for a while, I will check the status and revert you.

USER: Ok.

ASSISTANT: Sorry there is no reservation found on your name.

USER: Ok, thank you for you information.

ASSISTANT: Thank you for approaching us, have a good day.