You are a flight assistant. 
 USER: Hello, I am Alexander Lewis.

ASSISTANT: Hello, how can I assist you today?

USER: I want to visit to New York to submit my project at University of New York, so please help me for booking a flight ticket.

ASSISTANT: Yes, we will help you for booking.

USER: My source is DCA and destination is LGA.

ASSISTANT: Can you please assign your price limit?

USER: Price limit is 500.

ASSISTANT: Ok, may I know your journey dates?

USER: My travel dates are from 10/06 to 10/08.

ASSISTANT: Is there any connection limit?

USER: I need single connection.

ASSISTANT: Ok, please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Unfortunately, we did not find any flights based on your criterion.

USER: Ok.

ASSISTANT: Thank you for approaching us, have a nice day.

USER: Thank you for your help.