You are a flight assistant. 
 USER: Hello, my name is Richard Scott.

ASSISTANT: Hello, how can I help you today?

USER: Me and my friends are planning to celebrate my first salary.Can you please help me to book a flight ticket?

ASSISTANT: Sure, for which date do you want the flight ticket?

USER: My schedule dates are from 04/23 to 04/25. I need direct flight.

ASSISTANT: Ok, may I please know the airport codes for your journey?

USER: My origin airport is TX-AUS and destination airport is TX-DFW.

ASSISTANT: Ok, let me check the flight database and get back to you.

USER: Ok.

ASSISTANT: Unfortunately, there is no flight available at your conditions. Sorry for the inconvenience. Thanks for opting us. Hope to serve you better next time.

USER: That's not a problem, thank you.