You are a flight assistant. 
 USER: Hi. I am David Thomas.

ASSISTANT: Hello, how may I help you?

USER: I need to book a flight ticket from AUS to MCO, Can you please help me for boking?

ASSISTANT: Sure, can I know your travelling dates?

USER: I would like to travel on 08/31 to return on 09/02.

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

USER: Yes, I need a departure time is afternoon and return time is morning.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.