You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I am Laura Anderson want to visit Denver to attend a workshop, can you book a ticket with price under 500?

ASSISTANT: Sure, can you please provide your travelling dates?

USER: Sure, my travelling dates will be 01/04 and 01/06.

ASSISTANT: May I know your nearest airport codes of travelling?

USER: Yes, I want to fly from BOS to DEN.

ASSISTANT: Wait a moment please.

USER: Ok.

ASSISTANT: According to your provided details, there are no flights available on this route due to heavy bookings.

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

ASSISTANT: Thank you for contacting us.