You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I would like to change my recent reservation due some health issues, can you please help me with that?

ASSISTANT: Sure, I will help you in changing the flight ticket.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, myself Karen Harris.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: That's ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for checking out.