You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How best can I help you today?

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

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

USER: Thank you for accepting my request.

ASSISTANT: Can you please help me out by providing your name, to check your reservation status?

USER: Myself Margaret Hernandez.

ASSISTANT: Thank you for providing your name. Please, be on hold for a while. I will check your reservation status and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to inform you that, we have not found any active reservation on your name in our records.

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

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