You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Can you please help me with booking a flight ticket from DEN to ORD?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My travelling dates are from Aug 19-21.

ASSISTANT: Can I know your name please?

USER: Alexander Nelson here.

ASSISTANT: Do you need any specifications?

USER: No.

ASSISTANT: Sorry, there are no flights found.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.