You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you now?

USER: I need to book a flight ticket from IAD to LAS to enjoy river rafting.

ASSISTANT: Sure, I am oblige to help you with that. Can you please provide your preferable dates of travelling? Do you have any connection limit?

USER: Sure, my travelling dates are Mar 8 and Mar 10. I prefer maximum 1 connection in between journey.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I would prefer depart time at evening.

ASSISTANT: Can I know your name to book the flight ticket?

USER: Sure, Jennifer Perez here.

ASSISTANT: Please wait a moment to check the flights.

USER: Please make sure I want to fly in a economy class.

ASSISTANT: We regret to inform you that, there are no flights moving to your region with your requested preferences.

USER: Ok, no issues. Thank you for your assistance.

ASSISTANT: Thank you for contacting us, hope you have a great day.