You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I Assist you today?

USER: I want to attend a Seminar in Philadelphia. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, may I know your planned trip dates?

USER: My travelling dates are Apr 19 and Apr 21.

ASSISTANT: May I know your airport codes?

USER: My airport codes are HOU and PHL.

ASSISTANT: Do you have any connection limit?

USER: I prefer single connecting flight.

ASSISTANT: Any other requirements to be met?

USER: I don't have any other preferences.

ASSISTANT: May I know your good name?

USER: My name is Jack Williams.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.