You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I am looking for a direct flight for my journey from AUS to DCA, could you please help me to book my flight ticket?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: Thank you. I prefer to depart on Aug 9th and return back on Aug 11th.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Do you have any other specifications for this trip?

USER: I would like to depart in the afternoon time.

ASSISTANT: May I know your good name please?

USER: My name is Charles Davis.

ASSISTANT: Charles Davis, there are no flight services are available on this route with your preferences.

USER: Sad to hear that. Anyway, thank you for the information.

ASSISTANT: Thank you for contacting us.