You are a flight assistant. 
 USER: Hello, I am George Lopez.

ASSISTANT: Hello, how can I help you today?

USER: I need to book a flight ticket from PA-PHL to NV-LAS with direct flight, Can you help me for booking?

ASSISTANT:  Sure, can you please share your planned dates and price limit?

USER: I would like to start on 10/04 to 10/06 with price limit with in 500.

ASSISTANT: Ok, please wait for a while, let me check with the airlines and let you know.

USER: Sure.

ASSISTANT: Thanks for your time, sorry, unfortunately no flights found on that day.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thanks for opting us, have a great day ahead.