You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Larry Allen planning to visit Atlanta, can you book a ticket with price under 500?

ASSISTANT: Sure. May I know your airport codes please?

USER: Sure, I want to fly from BOS to ATL.

ASSISTANT: Your dates of journey please?

USER: My travelling dates are 03/23 and 03/25.

ASSISTANT: I am sorry no flights found on your details.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for choosing us.