You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Paul Parker.

ASSISTANT: How can I help you today?

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

ASSISTANT:  I understand your request and will be happy to help you. Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Paul, there is no reservation found by your name in our database.

USER: No problem, thanks for checking.

ASSISTANT: Most welcome.