You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Stephen Hernandez. I would like to book a flight ticket from DEN to BOS. Could you please help me out?

ASSISTANT: Sure, can I know your preferable dates?

USER: I am planning to start on 08/08 and return back on 08/10.

ASSISTANT: Sorry, there are no flights available on given schedule.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.