You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your name?

USER: Helen Davis here.

ASSISTANT: Can I know your travelling dates?

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

ASSISTANT: Can I know your connection limit?

USER: I prefer to fly in direct flight.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.