You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I address you?

USER: I am Katherine Edwards. I need to book a flight ticket from DFW to AUS, Can you please help me for booking?

ASSISTANT: Sure, on what dates are you willing to travel?

USER: I would like to travel on 08/19 08/21.

ASSISTANT: Is there any class preference?

USER: I am comfortable with any class.

ASSISTANT: How much fare are you expecting?

USER: I can pay up to 500.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for waiting, I regret to inform you that there are no flights obtained on your journey dates to book a flight ticket.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for picking us.