You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Need your assistance for booking from AUS in a direct flight.

ASSISTANT: Sure, can you share your travel dates please?

USER: My trip dates are on Feb 21 and 23.

ASSISTANT: May I know your depart airport code please?

USER: I have already mentioned.

ASSISTANT: Let me know your good name please.

USER: Deborah Turner here.

ASSISTANT: Ok, please share your arrival airport code.

USER: My destination airport code is IAH.

ASSISTANT: Do you have any other preferences?

USER: No.

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

USER: Ok, thank you.

ASSISTANT: Thank you for choosing us.