You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am looking to book a flight ticket from HOU to DCA. Can you help me for that?

ASSISTANT: Sure, can I know your travelling dates?

USER: My travelling dates are Oct 18 and Oct 20.

ASSISTANT: On which name should I reserve the flight ticket?

USER: My name is William Gonzalez.

ASSISTANT: Do you have any connection limit?

USER: I prefer to book a single connecting flight.

ASSISTANT: Do you have any other specifications?

USER: My depart time is evening.

ASSISTANT: Sorry, there are no flights found on given dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.