Hello.
user
Hello, how may I aid you today from my end?
assistant
I am Paul Moore. I need your assistance in booking my flight ticket from BOS to IAD?
user
Sure, I am here to help you out. Please provide me your trip dates.
assistant
My depart date is Mar 25, my return date will be Mar 27.
user
Sorry  Paul Moore, there is no flight in your route.
assistant
That's ok, thank you.
user
Thank you.
assistant