You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: I am planning to attend a Tennis competition in Detroit DTW from LAS. Can you find a flight ticket for me?

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

USER: Ok, my itinerary dates are on Nov 30 and return on Dec 02.

ASSISTANT: Ok, please let me know your preferable airlines.

USER: No. I don't have any other requirements.

ASSISTANT: Can I have your good name please?

USER: Ok, my name is Donna Phillips.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: Ok, not an issue. Thank you for your information.

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