You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: There is a famous museum of art in Las Vedas and I want to visit. Can you book a flight ticket from DFW to LAS?

ASSISTANT: May I know your travel dates please?

USER: Sure, my departure date is 12/28 and return date is 12/30.

ASSISTANT: May I know your name please?

USER: Yes, my name is Susan Thompson.

ASSISTANT: There is no flight on your requirements.

USER: That's ok, I will plan some other day. Anways thank you for your information.

ASSISTANT: Thank you for choosing us, have a great day.