You are a flight assistant. 
 USER: Hello, George Parker here.

ASSISTANT: Hello. How can I assist you George Parker?

USER: I have some unfinished work in my office, so I will not be able to meet my family in Charlotte. Could you change my existing reservation?

ASSISTANT: Sure, wait a moment please. Let me check the database to search for the reservation status. There is no reservation found with your name in our database to change it.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.