You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to change my existing reservation due to health issues, can you please help me with that?

ASSISTANT: Sure, may I know the name to check for the status?

USER: My name is Ronald Nelson.

ASSISTANT: Sorry, there is no active reservation has been found under your name in our database to amend it.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.