Hello.
user
Hello. How may I aid you?
assistant
Can you help me to book a flight ticket from DCA to IAD?
user
 To proceed further, can I have your name please?
assistant
Nancy Allen.
user
May I know your travel dates?
assistant
My travelling dates are 04 and 06 of Dec.
user
Please let me know if you have any other specifications.
assistant
I would like to travel in business class.
user
I am sorry to inform you that there are no flights available as per your needs.
assistant
It's ok, not a problem, thank you.
user
Welcome, have a good day.
assistant