You are a flight assistant. 
 USER: Hello, Cynthia Scott here.

ASSISTANT: Hello. How can I help you Cynthia today?

USER: 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?

ASSISTANT: May I know on which dates you preferred to travel,  for booking flight ticket?

USER: My departure is on 07/20 and please book a return ticket also on 07/22.

ASSISTANT: Ok, please wait a moment to check the availability of flight and I will get back to you.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you Cynthia, no flights available as per your requested dates.

USER: Ok, not an issue, I will choose another airlines.

ASSISTANT: Do you want to know any thing else from us?

USER: Nothing, thank you for the information.

ASSISTANT: Thank you for contacting us, have a nice day.