You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: I am Donna Thomas. I planned to meet my cousin in BOS, can you please help me to book a flight ticket from DTW?

ASSISTANT: Sure, I will help you with that. Can I have your travel dates please?

USER: I prefer to travel on Dec 21 and Dec 23.

ASSISTANT: Do you have any timings to travel?

USER: I prefer to depart in evening.

ASSISTANT: Sorry Donna Thomas, no flight is available to you on your dates.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Thank you for your information.