You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you at this moment?

USER: Can you help me to book a flight ticket from AUS to DEN?

ASSISTANT: Sure, I will assist you with that. Can you please mention your preferable travel dates?

USER: I want to take off on 19 and 21 of Mar.

ASSISTANT: May I know your name for further process?

USER: I am Patricia Taylor.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I am ok with any timing.

ASSISTANT: Do you have any limits on number of connections?

USER: I need a connecting flight.

ASSISTANT: Do you have any another specifications?

USER: I would like to return in the evening.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: It's ok, not a problem, thank you.