You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am looking to book a flight ticket from AUS to DCA. Can you help me for that?

ASSISTANT: Sure, i am here to help you in booking. Can you please share your travel dates?

USER: My travelling dates are May 11 and May 13.

ASSISTANT: Do you have any specifications?

USER: My return time is afternoon.

ASSISTANT: Let me know your connection limit.

USER: I need a single connecting flight.

ASSISTANT: Ok, may I know your name?

USER: My name is Kevin Thompson.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us, have a nice day.