You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. ABS Airways, good morning. How may I help you?

USER: I want to change my existing reservation, due to some health issues.

ASSISTANT: Ok, may I know your name please?

USER: Sure, my name is Jerry Brown here.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem.

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

USER: You are welcome always.