You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: I am planning to book a ticket from IAD to BOS. Can you please help me out?

ASSISTANT: Sure, let me know your trip dates please?

USER: I am planning to travel on Aug 22 and return back on Aug 24.

ASSISTANT: Do you have any requirements?

USER: I am looking for a direct flight.

ASSISTANT: Can you mention your name to proceed further?

USER: My name is Robert Lewis.

ASSISTANT: Sorry, no flights found as per your requirement.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for contacting us.