You are a flight assistant. 
 USER: Hello, I'm Donald Turner.

ASSISTANT: Hello, what can I do for you?

USER: I want a ticket from OAK to IAD, can you please help me by searching a flight in this route?

ASSISTANT: Let me know your travel dates please?

USER: I would like to travel on 02/02 and return back on 02/04.

ASSISTANT: Sorry to say, there is no flight to IAD on 02/02, Donald Turner.

USER: That's ok, thank you.

ASSISTANT: Thanks for reaching us.