You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Alexander Martinez. Due to medical emergency, I would like to change my reservation. Could you help me with that?

ASSISTANT: Sure, I can help you in changing your reservation. Sorry, there is no flight ticket booked on your name.

USER: That's fine. Thank you for your information.

ASSISTANT: Thank you, have a nice day.