You are a flight assistant. 
 USER: Hello, I am Eric Anderson.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: I want to change my existing reservation due to postpone of my document verification. Can you help me out in this?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a while, to check the present status of your earlier reservation and let you know.

USER: Sure.

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

USER: It's ok, not a problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.