You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: Please help me to book a flight ticket from BOS to DFW?

ASSISTANT: Sure, I am here to help you with that. Can I know your planned trip dates?

USER: My travelling dates are Aug 21 to Aug 23.

ASSISTANT: Is there any other requirements?

USER: I need a single connection of flight.

ASSISTANT: May I know your name?

USER: Jerry Wright.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available based on your travelling dates.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.