You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to attend for an interview in Austin, so please book a flight ticket from DEN to AUS?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: I want to fly on Aug 09, return on Aug 11.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Do you have any particular time for departing and returning?

USER: My depart time should be evening.

ASSISTANT: May I know your good name please?

USER: My name is Andrew Carter.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.