You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, may I know your name to modify your reservation?

USER: I am Mark Taylor.

ASSISTANT: Please wait a minute, I will check and get back to you.

USER: Ok.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.