You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samuel Wilson.

ASSISTANT: Wilson, how can I help you today?

USER: Due to my health problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Sure, I will help you with that. Please hold on for a while.

USER: Sure.

ASSISTANT: Sorry Wilson, no active reservation found by your name in our website.

USER: That's fine, thank you for your service.

ASSISTANT: My pleasure, have a great day.