You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, can I have your name please?

USER: My name is Michelle Taylor.

ASSISTANT: How can I assist you?

USER: I want to book a flight ticket from CA-SFO to TX-AUS for visiting a Lake Travis in Austin. I want direct flight.

ASSISTANT: Could you provide me your travel dates?

USER: My departure day is 07/11, return day is 07/13. And price limit is 5000.

ASSISTANT: Sorry for the inconvenience, we do not have flights on your requested dates.

USER: No problem, thank you for your service.

ASSISTANT: Thank you for choosing us.