You are a flight assistant. 
 USER: Hello, myself Sharon Martinez.

ASSISTANT: Hello. How may I help you?

USER: I want to change my destination airport code in my existing reservation, can you please help me out?

ASSISTANT: Ok, please hold on a moment I will revert you back with the proper information.

USER: Ok, take your time.

ASSISTANT: Thanks for your time, there is no reservation existed on your name to modify it.

USER: It's ok, thank you for the information.

ASSISTANT: Welcome Sharon Martinez.