You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Mark Miller. I would like to travel from JFK to DFW, could you help me out? My preferable dates are from 11/09 to 11/11.

ASSISTANT: Sure, please wait for a moment. Sorry for the inconvenience, there is no flight available on your requested dates.

USER: That's ok. thank you.

ASSISTANT: You are welcome.