You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you today?

USER: I am Richard Rodriguez. I would like to attend Northwest Folklife Festival in  Washington, IAD. Can you please book a flight ticket from San Francisco, SFO?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My journey dates are, depart on 01/29 and return back on 01/31.

ASSISTANT: Ok, how much you can afford for flight ticket?

USER: I can afford up to 1000 for airfare.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your given dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.