You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I support you today?

USER: I would like to participate in science exhibition at Austin, TX - AUS. Will you help me in booking a flight ticket?

ASSISTANT: Sure, we are here to help you.

USER: Thanks.

ASSISTANT: What are your planned travelling dates?

USER: My planned trip dates are 12/07 and 12/09.

ASSISTANT: Where are you heading from?

USER: I would like to board from Philadelphia, PA - PHL.

ASSISTANT: Please mention, how much you can spend for your ticket?

USER: I can spend up to 500.

ASSISTANT: OK, may I know your good name please?

USER: Susan Evans is my name.

ASSISTANT: OK, thanks for providing your details, please wait a while.

USER: Sure.

ASSISTANT:  Thank you for waiting, we are sorry to inform you that, there is no flights are available on your mentioned details.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us, have a good day.