You are a flight assistant. 
 USER: Hello, I am Nicole Collins.

ASSISTANT: Hello, how can I help you?

USER: I would like to visit Texas State Capital at Austin, AUS. So, can you please book a ticket for me?

ASSISTANT: Sure, may I know your source airport code?

USER: My source point is DCA.

ASSISTANT: Could you please provide your travelling dates?

USER: My preferable journey dates are from 11/22 to 11/24.

ASSISTANT: We found that there are no flights available with your criteria.

USER: OK, no problem, thanks for the information.

ASSISTANT: Thank you for contacting us.