You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Margaret Lopez here. I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you please change my reservation?

ASSISTANT: Sure, just a moment please.

USER: Ok.

ASSISTANT: I am sorry no reservation found on your name.

USER: That's ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for informing.