You are a flight assistant. 
 USER: Hi, I am Ashley Thompson.

ASSISTANT: Hello. How can I serve you?

USER: I would like to book a flight ticket to Washington DC-DCA to attend client meeting on 12/30. Can you help  me to book a flight ticket?

ASSISTANT: Sure, Can you let me know your return date?

USER: I intend to return on 01/01.

ASSISTANT: Please share me your source airport code.

USER: I need to start from Oakland, CA-OAK.

ASSISTANT: Do you have any connection limit?

USER: I prefer one connection.

ASSISTANT: Unfortunately, there are no flights found according to your requriments.

USER: Ok, no problem. Thanks for your help.

ASSISTANT: Thank you for remaining positive.