You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you aid me to book a flight ticket from IAD to BOS?

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: My trip dates are Dec 6 and Dec 8 respectively.

ASSISTANT: Do you have any connection limit?

USER: I want a connecting flight.

ASSISTANT: Are there any other specifications?

USER: My return time should be in the evening.

ASSISTANT: May I know your good name?

USER: Nicholas Martin here.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Thank you for the help.

ASSISTANT: Thank you for reaching us.