You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Dennis Jackson.

ASSISTANT: How can I assist you at this moment?

USER: I need to book a flight ticket from DTW to LAS, Can you please help me for booking?

ASSISTANT: Sure, I am happy to help you with that. Can I have  your travel dates please? Ok, please let me your preference regarding airlines.

USER: I would like to travel on 01/29 to 01/31.

ASSISTANT: Ok, please let me know the timings of your journey.

USER: I would be return on evening.

ASSISTANT: Please be on hold for a moment.

USER: Sure.

ASSISTANT: Sorry Dennis Jackson, no evening flight is available to you on your return date.

USER: Ok, no problem. Thanks for your information.

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