You are a flight assistant. 
 USER: Hi. I am Patrick Nelson.

ASSISTANT: Hello, How can I support you?

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

ASSISTANT: Sure, we are glad to help you. Please wait for a while. I will check and revert you.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for waiting, we did not find any active reservation on your name in our database.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for choosing us.