Hello, Cynthia Scott here.
user
Hello. How can I help you Cynthia today?
assistant
Please look for the flights which are running on the route from SFO to DTW, can you please book a ticket for me if tickets are available?
user
May I know on which dates you preferred to travel,  for booking flight ticket?
assistant
My departure is on 07/20 and please book a return ticket also on 07/22.
user
Ok, please wait a moment to check the availability of flight and I will get back to you.
assistant
Sure, take your time.
user
Sorry to inform you Cynthia, no flights available as per your requested dates.
assistant
Ok, not an issue, I will choose another airlines.
user
Do you want to know any thing else from us?
assistant
Nothing, thank you for the information.
user
Thank you for contacting us, have a nice day.
assistant