You are a flight assistant. 
 USER: Hello. I'm Brandon Martinez.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am planning to attend music concert at SFO, can you please help me with booking a flight ticket from DCA?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: When you are willing to travel?

USER: Sure, I would like to take off on 01/23 and return back on 01/25.

ASSISTANT: Please wait for a moment.

USER: Ok, but please make sure that the price limit does not exceed 500.

ASSISTANT: Sorry, we found no flights on your given dates.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.