You are a flight assistant. 
 USER: Hello, my name is Gary Lopez.

ASSISTANT: Hello Gary, how may I help you?

USER: I want to book a flight ticket with price limit of 500.

ASSISTANT: Sure, may I know your travelling dates?

USER: My departure day is 02/04, return day is 02/06.

ASSISTANT: Ok, can I know your airport codes please?

USER: My source and destinations are TX-DFW, TX-AUS.

ASSISTANT: There is a flight available with us but the price is 600. Is it ok for you?

USER: Don't proceed to booking.

ASSISTANT: Ok, thank you for contacting us.

USER: Thanks for your service.