You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Kathleen Garcia, I want to book a flight ticket within my price limit 500.

ASSISTANT: Sure, can you provide me your travelling dates?

USER: Sure, my departure is 08/25 and I will return on 08/27.

ASSISTANT: OK, may I know your airport codes?

USER: Sure, I am planning to surprise my mother on her birthday in DC - DCA and my origin from CO - DEN.

ASSISTANT: OK, please wait for a minute, let me check and revert you.

USER: Sure.

ASSISTANT: Thanks for waiting, I found a flight in Southwest with your specifications. Flight number is 1009 with single connection and price of 600. Shall I proceed with booking?

USER: Don't proceed, my fare is 500.

ASSISTANT: OK.

USER: Thank you for your service.

ASSISTANT: Thank you.