You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Can you please book a ticket from DEN to EWR to attend Sports festival?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: My travelling dates are Dec 6 and Dec 8.

ASSISTANT: Are you ok with connecting flight?

USER: I want single connection.

ASSISTANT: Do you have any more specifications?

USER: My return time is evening.

ASSISTANT: May I know your name to book a flight ticket?

USER: I am John Nelson.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok.

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

USER: Ok, Thank you.

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