You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm John Thompson.

ASSISTANT: How can I help you John Thompson?

USER: I am planning to visit Ford's theater at SFO, can you please help me with booking a flight ticket from CLT?

ASSISTANT: Sure, may I know your travelling dates to proceed further?

USER: Sure, I would like to take off on 03/19 and return back on 03/21.

ASSISTANT: Hold on for a moment please, let me check the flights availability on this route.

USER: Sure. Make sure that the price limit should not exceed 500.

ASSISTANT: Sorry to inform you that, there are no flights available on this route due to heavy bookings.

USER: Ok, no issues. I will try another way to complete my trip. Thank you for the information.

ASSISTANT: Thank you for choosing our services.

USER: You are welcome.