You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Can you avail me to book a flight from Washington to Oakland?

ASSISTANT: Sure, let me know your trip dates?

USER: My travel dates are Feb 07 and 09.

ASSISTANT: May I know your airport codes?

USER: My airport codes are DCA and OAK.

ASSISTANT: Do you have any connection limit?

USER: I prefer direct flight.

ASSISTANT: Is there any other specifications?

USER: I prefer to travel in economy class.

ASSISTANT: May I know your name please?

USER: Jonathan King here.

ASSISTANT: There are no flights available in your route.

USER: Ok, thank you.

ASSISTANT: Thank you for choosing us.