You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Charles Clark. I would like to travel from SFO to DTW, could you help me out?

ASSISTANT: May I know your trip dates?

USER: My preferable dates are from 11/09 to 11/11.

ASSISTANT: Sorry, there are no flights available as per your request.

USER: That's ok. Thank you, have a good day.

ASSISTANT: Most welcome.