You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Will you please make me a plane reservation from IAD to DEN?

ASSISTANT: Sure, may I know your trip dates?

USER: I will start on Apr 23rd and return on Apr 25th.

ASSISTANT: Do you need any layovers between your trip?

USER: Yes, I need 1 lay over within my route.

ASSISTANT: May I know your name to proceed further?

USER: I am Brenda Adams.

ASSISTANT: Do you need any other specifications?

USER: I would prefer to travel in business class from major cost airline.

ASSISTANT: We regret to inform you that there is no flights going on your way.

USER: That's alright, thanks for your assistance.

ASSISTANT: Thank you for contacting us.