Hello.
user
Hello, how can I help you at present?
assistant
Can you please help me to book a flight from DEN to DTW?
user
Sure, can I know your good name please?
assistant
I am Kevin Williams.
user
 When you are willing to travel?
assistant
My travel dates are July 18 to 20.
user
Do you need direct flight or connecting flight?
assistant
I prefer connecting flight.
user
Are there any other specifications?
assistant
My depart time should be morning.
user
Sorry to say that, there are no flights available on the routes of your journey.
assistant
No problem, thank you for the information.
user
Thank you for choosing us.
assistant