You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: Could you please help me to book a flight ticket from DEN to PHX?

ASSISTANT: Please provide your journey dates.

USER: My journey dates are Apr 03 and Apr 05.

ASSISTANT: Do you need any connection limit?

USER: I need a direct flight.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: May I know your name?

USER: I am Joseph Gonzalez.

ASSISTANT: There are no flights available on your routes.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for opting us.