You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, I am willing to help you for this. May I know your name please?

USER: Thank you. Myself Joseph Hernandez.

ASSISTANT: Please wait for a while. Sorry for inconvenience, no reservation is found under your name.

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

ASSISTANT: Thank you very much for contacting our agency.