You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Donald Brown. As I am a new joiner, I need to attend two days training session in my branch office at Denver, DEN. So, can you book me a flight from Washington, DC-DCA?

ASSISTANT: Sure, may I know your travelling dates?

USER: Yes, my travelling dates are 05/02 and 05/04.

ASSISTANT: Do you need any stopover within your journey?

USER: I need a direct flight.

ASSISTANT: Ok, please wait for a minute.

USER: OK.

ASSISTANT: There is no flight found matching with your requirements.

USER: That's ok.

ASSISTANT: Thanks for availing us.

USER: Thank you for the information.