Hi.
Hello. How can I assist you today?
I am Matthew Walker. I would like to book a ticket from IAD to  PHX, can you help me?
Sure, I am here to help you with that booking. Can you please provide your dates of travel?
My travel dates are 10/18 and 10/20.
Please wait for a moment.
Sure.
Sorry to say, there are no flights available on your route as per your given travel dates.
No problem, thanks for checking.
Thank you for contacting us. Have a great day.