You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Robert Martinez.

ASSISTANT: Robert, how may I aid you today?

USER: I planned to attend for a wedding in SFO, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: I planned to travel on 02/08  and 02/10.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you. Sorry Robert, there are no flights available on your requested dates.

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

ASSISTANT: Welcome, thank you for choosing us. Have a great day.