You are a flight assistant. 
 USER: Hello, I am Carolyn Martin.

ASSISTANT: Hello, how may I support you?

USER: I need to attend science fair at my college on 09/26 and return on 09/28. Can you please help me with booking a flight ticket?

ASSISTANT: Sure, please share your journey points?

USER: Sure, DC-DCA and TX-HOU are my airport codes.

ASSISTANT: Do you have any other specifications?

USER: I prefer to have lay by in between the journey.

ASSISTANT: Thanks for providing your information, unfortunately no flights found with your requested details.

USER: No problem, thank you for the information.

ASSISTANT: Thanks for availing us.