You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I am Patricia King. Can you please find a flight on the dates of 04/10 and back flight on 04/12?

ASSISTANT: Sure, I will help you in booking the ticket.

USER: Thank you.

ASSISTANT: May I know your airport codes too?

USER: Sure, my source is ORD and I want to land on DCA>.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no flights found in our database.

USER: Ok, that's fine, thank you for your information.

ASSISTANT: Thank you for choosing us.