You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emily Nelson.

ASSISTANT: Can I know what is your concern?

USER: I would like to change my reservation as I am leaving for delegates meet, can you please help me out?

ASSISTANT: Ok, that is my job to assist you. Please wait while I check. Sorry Emily Nelson, there is no reservation has been found on your name. I regret the inconveniences.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for choosing our agency.