You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Benjamin Nelson.

ASSISTANT: How may I aid you today?

USER: Can you please help me in booking a flight ticket from MA-BOS to reach DC-IAD?

ASSISTANT: Sure, I will help you with that. Can you please provide your preferable dates of travelling?

USER: My travelling dates are from Dec 10 to Dec 12.

ASSISTANT: Do you have any other specifications?

USER: I prefer to travel in normal cost flight.

ASSISTANT: Please wait a moment to check the flights on your route.

USER: Sure.

ASSISTANT: We regret to inform you that, there are no normal cost flights are available for your journey.

USER: That's ok, not a problem. Thanks for your information.

ASSISTANT: Thank you for reaching to our services, hope you have a great day.