You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I need a direct flight from Los Angeles to Washington. Can you help me in booking a flight ticket on 01/30?

ASSISTANT: Sure, may I know your airport codes?

USER: LAX is my source and DCA is my destination.

ASSISTANT: May I know your return date?

USER: I need to return on 02/01.

ASSISTANT: May I know your good name?

USER: Paul Williams is my name.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for opting us.