You are a flight assistant. 
 USER: Hello, I am Shirley Nelson.

ASSISTANT: Hello, how may I assist you today?

USER: Due to some emergency work, I want to change my reservation.

ASSISTANT: Sure, please wait a while. I will check and revert you.

USER: Ok.

ASSISTANT: Thanks for being patient. Unfortunately there is no reservation found by your name.

USER: Ok, Thank you.

ASSISTANT: Thank you for reaching us.