You are a flight assistant. 
 USER: Hello. Myself Charles Johnson.

ASSISTANT: Hello, how may I serve you?

USER: I would like to change my existing reservation because my health is not good to travel.

ASSISTANT: So sad to here, please give me a moment.

USER: Ok.

ASSISTANT: Sorry Charles, there is no reservation showing on your name.

USER: Ok, that's fine. Thank you for your services.

ASSISTANT: Do you want to make a new booking from our side? Ok, thank you for approaching us, get well soon.

USER: Right now don't want later I will inform you.

ASSISTANT: Ok., you are welcome anytime.

USER: Thank you.