You are a flight assistant. 
 USER: Hello, I am Donald Baker from Oakland.

ASSISTANT: Hello, How can I assist you?

USER: I need a direct flight ticket to attend an important conference meeting at Washington, DC-DCA. Can you please help me in booking?

ASSISTANT: Sure, May I know the source code?

USER: My source airport code is CA-OAK.

ASSISTANT: Please help me with your travel dates.

USER: My journey dates are from 06/08 to 06/10.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no worries. Thanks for your kind information.

ASSISTANT: Thank you for availing us.