Hello. I am Katharine Hall here.
user
Hello, how may I serve you at this moment?
assistant
 I need to book my ticket from DEN to DTW. Can you please help me with booking a flight ticket ?
user
Sure, I will help you. Please send your travelling dates.
assistant
My planned travel dates are from Apr 26 to Apr 28.
user
Do you have any class or time preferences?
assistant
Yes, my return time should be in the evening.
user
Do you have any connection or airline preferences?
assistant
I need a connecting flight in my journey.
user
Sorry, there is no flight available with your given requirements on your requested dates.
assistant
Not a problem, thank you for the information.
user
You are welcome, have a nice day.
assistant