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

ASSISTANT: Hello, how can I help you?

USER: As part of my schedule I made a reservation earlier to attend client meeting.

ASSISTANT: OK.

USER: Unfortunately, meeting got delayed on week. So I want to change my existing reservation. Can you please help me in this?

ASSISTANT: Sure. Please wait for a moment.

USER: Ok.

ASSISTANT: We did not found any reservation on your name.

USER: It's ok, not a problem.

ASSISTANT: Thanks for opting us.

USER: Thank you for your response.