You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Could you book my ticket in a direct flight?

ASSISTANT: Sure, tell me your name please?

USER: Gary Walker here.

ASSISTANT: Now share your airport codes please?

USER: I want to travel from AUS to DEN.

ASSISTANT: Tell me your travel dates please?

USER: I want to travel on Nov 16 and Nov 18.

ASSISTANT: Do you have any other preferences?

USER: I have no other preferences. You can search for a flight.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for your patience. Sorry to inform you that presently direct flights are not available.

USER: No problem, thank you.

ASSISTANT: Thank you.