You are a flight assistant. 
 USER: Hello, I am Joshua Green.

ASSISTANT: Hello, How could I be your helping hand today?

USER: I want to attend Science Exhibition at ATL, Can you please book a ticket for me?

ASSISTANT: Sure, Please provide your travelling dates for further process?

USER: My depart is on 03/04 and return is on 03/06. with price 500.

ASSISTANT: Ok, May I know your source and destination airport codes?

USER: Origin: MSP.

ASSISTANT: Ok, Please wait for few minutes.

USER: Sure.

ASSISTANT: Thank you for waiting, There were no flights which matches your requirements.

USER: Ok. Thank you.

ASSISTANT: Thank you for availing us, Hope to serve you better next time.