Hello.
Hello, how can I guide you for today?
 As I am a scientist, I want to attend science festival with my students at Washington.
Can you please share on what dates you are willing to travel?
Can you help me to book a ticket from SFO to DCA?
Can you please provide your travelling dates?
My trip dates are 05/27 and 05/29.
Do you have any other requirements that you are looking for?
I need only direct flight.
May I know your name to proceed further?
Thomas Walker here.
Sorry, there are no flights available on your requested dates.
No problem, Thanks for the information.
Thank you for contacting us, have a nice day.