Hi, I am Kathleen Green.
user
Hello. How can I aid you?
assistant
I would like to go for a round trip to San Francisco, CA - SFO, so I need to book a direct flight.
user
Sure, I can help you. Can  I  know your travelling dates?
assistant
Sure, my trip dates are on 07/28 to 07/30.
user
Give me a minute.
assistant
Sure.
user
Thanks for being waiting. Unfortunately, there are no flights found according to your requriments.
assistant
No problem, thanks for your kind service.
user
Thank you.
assistant