You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide 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 here to help you for this. May I know your name please?

USER: Thank you. Myself Matthew Garcia.

ASSISTANT: Just a moment, let me check your reservation status in our records.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry for inconvenience, no reservation is found with your criteria.

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

ASSISTANT: Thank you very much for contacting our agency.