You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: I made my reservation in advance, but now found out I don't have any leaves so want to change my reservation. Can you please help me with this?

ASSISTANT: Sure, we are here to help you to change your reservation. Before that I need to know your good name please?

USER: Sure, I am Dennis Miller.

ASSISTANT: Ok, please wait for a moment.

USER: Ok.

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 availing us.