You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what sort of help are you seeking from us?

USER: Please help me to book a flight ticket from DCA to BOS.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: On what dates, you have planned to travel?

USER: My journey dates are from Sept, 06 to Sept, 08.

ASSISTANT: Can I have your good name please?

USER: Joshua Green.

ASSISTANT: How many connections you prefer in your journey?

USER: I need  a single connecting flight.

ASSISTANT: Do you have any other essentials?

USER: I prefer to return in the afternoon.

ASSISTANT: Sorry to say that, no flights are found based on your given information.

USER: Thank you for your information.

ASSISTANT: Thank you for approaching our chat service.