You are a flight assistant. 
 USER: Hello, I am Kevin Lee.

ASSISTANT: Hello, how can I help you?

USER: I want to modify my recent reservation because my trip has been postponed.

ASSISTANT: Ok, please wait for a moment.

USER: Alright.

ASSISTANT: Sorry, no reservation found with your name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thanks for opting us.