Hi, my name is Amy Johnson.
Hello, how can I be at your service?
Please book a ticket to my friend on 07/21 with the price limit of 500.
Ok. Can you please  share your airport codes?
Sure. My flight codes are from IAD to AUS.
May I know your return date?
I have to return on 07/23.
We found a Southwest airline flight with 1017 number was available that matching your requirements.
Ok, proceed with this flight.
Your ticket has been confirmed.
Thank you for your assistance.
Thanks for reaching us.