You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please make a reservation from DCA to DEN?

ASSISTANT: Sure, may I know your trip dates?

USER: My journey dates are on Oct 13th and 15th.

ASSISTANT: Do you have any other requirements?

USER: I need a direct flight.

ASSISTANT: Can I know your name?

USER: My name is Paul Wilson.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, no problem. Thank you.

ASSISTANT: Most welcome.