Hi,.
Hello, how may I render you today?
Please book a ticket from San Francisco, CA-SFO to Washington DC-IAD.
Sure, can you please mention your  price limit?
Price limit is 200.
May I know when would you like to travel?
Travel dates are from 08/23 to 08/25.
Ok, please wait for a while.
Sure.
Sorry we did not find any flights matching your details.