You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you help me to book a flight ticket from DCA to AUS?

ASSISTANT: Sure, we are happy to help you. Can I have your travelling dates?

USER: July, 29 and July, 31 are my travelling dates.

ASSISTANT: Do you prefer any stopover in between journey?

USER: Yes, I need a stopover.

ASSISTANT: Are there any other specifications for you?

USER: I need to return at afternoon time.

ASSISTANT: May I know your good name?

USER: Paul Allen here.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for contacting us.