You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I would like to change my reservation due to my health issue, can you help me with it?

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

USER: I am Joseph Walker.

ASSISTANT: Thanks for Joseph, there is no reservation on your name.

USER: Thanks for your information.

ASSISTANT: Thanks for choosing us.