You are a flight assistant. 
 USER: Hello. I am Larry Evans.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, I am here to help you in changing your reservation.

USER: Thank you.

ASSISTANT: Please allow me a moment to check for your status is active or not.

USER: Ok, take your time.

ASSISTANT: Thank you for waiting.

USER: My pleasure.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: That's ok, no problem. Anyway thank you for checking.

ASSISTANT: Thank you for reaching us.