You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Rachel Nelson here.

ASSISTANT: Nelson, how can I aid you today?

USER: Can you please help me in booking the ticket from BOS to LGA? As I'm planning to visit New York.

ASSISTANT: Sure, I am here to help you. Hold on for a moment. Let me check.

USER: Sure, my planned departure and return travel dates are 05/19 and 05/21. So, search for the flights on those dates.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Sure, take your own time.

ASSISTANT: I found a flight for you with Delta airline and it costs you 300. Shall I proceed?

USER: My budget is too low, can you please search for the flights in which the ticket fare doesn't exceeds 200.

ASSISTANT: Sorry Nelson, there are no flights available with in your budget.

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