You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am planning to visit Museum of Nature and Science at Denver, could you please help me with booking a flight ticket from AUS to DEN?

ASSISTANT: Sure, can I know the trip dates please?

USER: I would like to depart on June 25th and return on June 27th.

ASSISTANT: Do you have any requirements?

USER: I am looking for a direct flight.

ASSISTANT: May I know your name please?

USER: I am Anthony Campbell.

ASSISTANT: Sorry, there are no flights available as per your request. Thank you for approaching us.

USER: Ok, not an issue. Anyways, thank you for the information.