You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Brian Hill. I want to book a ticket from DCA to AUS, can you help me?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: My travel dates are May 21 and 23.

ASSISTANT: Do you have any specifications?

USER: My departure time is in the morning and return time is in the afternoon.

ASSISTANT: Do you have any preferences about class?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other preferences?

USER: I need a single connecting flight.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: No problem, thanks for checking.

ASSISTANT: Welcome, have a great day.