You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you?

USER: I am Samuel Barker. I am planning to book a ticket from DTW to SEA. Can you please help me out to book a ticket for me?

ASSISTANT: Sure, may I know your departure and arrival day?

USER: I would like to travel on 01/28 and return back on 01/30.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: That's fine. Thank you for your help.

ASSISTANT: You are welcome.