You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: I am planning to visit Las Vegas, can you please book me a ticket from DEN to LAS?

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

USER: My preferable journey dates are from 06/18 to 06/20.

ASSISTANT: Ok, please wait a moment.

USER: Please find me a direct flight.

ASSISTANT: Sure, I will check with that. Sorry to inform you that no flight is available to you.

USER: Ok, not an issue. I will find any alternate for this trip.

ASSISTANT: May I know your name please?

USER: My name is Daniel Evans. Thank you for providing information.

ASSISTANT: Ok, thank you for choosing us.