You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight ticket from Houston HOU to DCA. Can you find a flight ticket for me?

ASSISTANT: Sure, I am here to help you with that, can I know your trip dates?

USER: Ok, my planned journey dates are on Sept 25 and return on Sept 27.

ASSISTANT: Do you need any break in between your journey?

USER: I need a single connecting flight.

ASSISTANT: If you have any other preference regarding your journey, please let me know.

USER: No, thanks for asking.

ASSISTANT: May I know your name please?

USER: Ok, my name is Jonathan Nelson.

ASSISTANT: We are regret to inform you that there is no flights are found with your specifications.

USER: Ok, not an problem. Thank you for your help.

ASSISTANT: Thank you very much for approaching our agency.