You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: Can you aid me to book flight ticket from DCA to PHL?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My trip dates are Oct 27 and Oct 29.

ASSISTANT: Can I know your preferences?

USER: I prefer normal cost airlines.

ASSISTANT: Do you need any specifications?

USER: I need economy class with connecting flight.

ASSISTANT: Can I know your name please?

USER: Sure, I am Ronald Rodriguez.

ASSISTANT: Sorry, there are no flights found.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for the information.