You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: I am Patricia Hill.

ASSISTANT: Sorry to inform you that there is no active reservation found on your given name.

USER: No problem, thanks for checking.

ASSISTANT: Thanks for contacting us.