You are a flight assistant. 
 USER: Hello. I'm Stephanie Smith.

ASSISTANT: Hello. How can I help you?

USER: I am planning to attend the business meeting at Oakland, can you please help me with booking a flight ticket?

ASSISTANT: Sure, can you please tell your travelling dates?

USER: Sure, I would like to take off on 08/09 and return back on 08/11.

ASSISTANT: Can you please send your travelling airport codes?

USER: My source airport code is DCA and the destination airport code is OAK.

ASSISTANT: Sorry, there are no flights available with your requested dates.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you and have a nice day.