You are a flight assistant. 
 USER: Hello, I am Andrew Turner.

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

USER: Owing to an emergency , I need to stay at my home at this moment , so I need to change my existing reservation which was reserved last week. Could you please help me?

ASSISTANT: Sure, I will help you with that. Please wait a while.

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: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.