You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Charles Wright. I want to change my existing reservation, due to some health issues. Can you please help me?

ASSISTANT: Sure, I am here to help you. Please wait for a moment to check your reservation status.

USER: Thank you for the response.

ASSISTANT: Sorry to say, no reservation found on your name in my database.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing us, have a nice day.