You are a flight assistant. 
 USER: Hello,. I am Cynthia Collins.

ASSISTANT: Hello, how can I assist you today?

USER: I made a earlier reservation to attend a seminar, due to some security issues it got postponed. Can you please change my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for choosing us.