You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in booking a flight ticket from DCA to AUS?

ASSISTANT: Sure, please share me your travelling dates?

USER: I would like to travel on Oct 18 and return on Oct 20.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Do you have any connection limit?

USER: I need connecting flight.

ASSISTANT: Is there any other specifications?

USER: My return time should be afternoon.

ASSISTANT: May I know your name?

USER: Betty Lopez here.

ASSISTANT: Sorry, there were no flights with your given details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.