You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Stephen King. Can you help me to book a flight ticket from DCA to BOS?

ASSISTANT: Sure, I am here to help you out. Please share me your trip dates.

USER: Ok, my travel dates are 09/27 adn 09/29 respectively.

ASSISTANT: Sorry King, there is no flight in your route with your preferred dates.

USER: Ok, not a problem I will book next week. Thank you for the information.

ASSISTANT: Thank you for reaching us.