You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

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

ASSISTANT: Sure, I will help you with that. May I know your good name?

USER: My name is Helen Wilson.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation found on your name to change.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.