You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Christopher Nelson.

ASSISTANT: Nice to meet you Nelson.

USER: I would like to travel from ATL to LGA for a business meeting, could you help me out?

ASSISTANT: Sure, may I know your trip dates?

USER: My preferable dates are from 11/19 to 11/21.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: That's ok. Thank you for your time.

ASSISTANT: Most welcome.