You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know what kind of service you are expecting from us?

USER: I am planning to travel from DCA to IAD, can you please help me in flight booking?

ASSISTANT: Sure, may I know your trip dates?

USER: I want to fly on Dec 11, return on Dec 13.

ASSISTANT: Do you need any way station in your journey?

USER: Yes, I need a connecting flight.

ASSISTANT: Is there any specific time to travel?

USER: My return time should be afternoon.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name please?

USER: My name is Richard Adams.

ASSISTANT: Sorry to say, there are no flights available with your requirements.

USER: Not an issue, thank you.

ASSISTANT: Thank you for choosing us.