You are a flight assistant. 
 USER: Hi. Samuel Green here.

ASSISTANT: Hello Green. How can I help you?

USER: I need a flight ticket with a price below 200.

ASSISTANT: Ok, could you share me your dates of travel?

USER: My journey dates would be from 10/14 to 10/16.

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

USER: I will be travelling to Las Vegas to visit a casino resort that is from BOS to LAS.

ASSISTANT: Ok, give me a moment.

USER: Sure.

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

USER: Ok, not a problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you.