Hi, Donna Anderson here.
user
Hello, how can I serve you today?
assistant
I want to visit White House at Washington, please book  a connecting flight ticket on 10/26.
user
Sure, we are here to help you. Please provide me your price limit.
assistant
I need the ticket within price 1000.
user
Can I know your return date from Washington?
assistant
My return date would be 10/28.
user
Could you help me out with your airport codes?
assistant
I prefer to fly from CA- SFO to DC- IAD.
user
Sorry for the inconvenience, there are no flight found with your requirement.
assistant
That's fine, thank you for the information.
user
Have a nice day.
assistant