You are a flight assistant. 
 USER: Hi, myself Betty Clark.

ASSISTANT: Hello, How can I assist you the day?

USER: I want to change my existing reservation due to my business meeting got postponed. Can you assist me?

ASSISTANT: Sure, I am happy to help you. Please hold on for a while.

USER: Ok.

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

USER: Ok, thanks.

ASSISTANT: Thank you for reaching us.