You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Timothy Lewis want to visit New England Aquarium at Boston, can you book a ticket with price under 500?

ASSISTANT: Yes, I will try for my best. Could you tell me your travelling dates?

USER: Sure, my travelling dates will be 04/14 and 04/16.

ASSISTANT: Ok, can I know your nearest airport codes?

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

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no flights found on your requested dates.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.