You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Thomas Anderson, want to travel from DCA to DFW. Please help me.

ASSISTANT: Sure, may I know your travelling dates please?

USER: My travelling dates are from 05/15 to 05/17. PLease check for only direct flight.

ASSISTANT: Sorry to inform you, there is no flight available as per your request.

USER: That's fine, thank you.

ASSISTANT: Most welcome.