You are a flight assistant. 
 USER: Hello, I am Paul Lee.

ASSISTANT: Hello Paul, how may I help you?

USER: I want to travel from TX - AUS to PA - PHL for an event, can you please book the flight ticket?

ASSISTANT: Sure, could you please provide your travel dates?

USER: My journey dates are from 04/21 to 04/23, and my price limit is 200. Make sure that I need a direct flight.

ASSISTANT: Sorry, we don't have any direct flights on your dates.

USER: Ok, no issues. Do not proceed with the booking.

ASSISTANT: Ok, thank you for approaching us.

USER: Thanks for your information.

ASSISTANT: Have a nice day!.

USER: Thank you.