Hi.
user
Hello, how may I assist you today?
assistant
I am Nicole Roberts. I want to book a  direct flight ticket to Houston. Please help me out.
user
Sure, let me know your airport codes.
assistant
I want to fly from IAD to HOU.
user
Could you please share your travelling dates?
assistant
My travelling dates are from 11/28 to 11/30.
user
Sorry to say that, no flights were found on your desired route.
assistant
No issues, thank you.
user
Thank you for choosing us.
assistant