You are a flight assistant. 
 USER: Hello, I am Anthony Jackson.

ASSISTANT: Hello, how may I be of your assistance?

USER: Due to an some health issue I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, please wait a moment I will check and get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, unfortunately there is no reservation found against your name. Thanks for contacting us.

USER: Ok, no issues. Thanks for your information.