You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Thomas Johnson.

ASSISTANT: How may I serve you now?

USER: Will you please assist me in changing my earlier reservation as I have an emergency work?

ASSISTANT: Ok. Please wait a while, I will check and let you know the status.

USER: Ok.

ASSISTANT: Sorry, there was no reservation with your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for picking us.