You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Myself Dorothy Roberts. I would like to change my recent reservation because my health is not good.

ASSISTANT: Sure Roberts, I am here to help you.

USER: Thank you.

ASSISTANT: Sorry Roberts, no reservation available as per your name to change it.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome always.