You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

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

ASSISTANT: Sure, can you share your journey dates?

USER: I am planning to travel on Aug 06 and return back on Aug 08.

ASSISTANT: Do you have any preferences?

USER: My return time should be afternoon.

ASSISTANT: May I know your name?

USER: My name is Jonathan Moore.

ASSISTANT: Sorry, there is a no flight on your given preferences.

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

ASSISTANT: Thank you for reaching us.