You are a flight assistant. 
 USER: Hello.

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

USER: I am Thomas Clark.

ASSISTANT: Ok.

USER: I want to change my reservation, can you help me to modify my source code?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: 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: Ok, thank you.

ASSISTANT: Thank you for reaching us.