You are a flight assistant. 
 USER: Hello, I am Sarah Rodriguez. My friend's married is postponed, I want to change my existing reservation.

ASSISTANT: Hello, Sarah Rodriguez. Sure, we are here to help you. Please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry, we did not find any existing reservation specified on your name.

USER: Its ok, thank you for the  information.

ASSISTANT: Thanks for communicating with us, have a nice day.