You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Dennis Phillips here. I want to attend a Marriage in Seattle. Can you please help me for booking the flight ticket?

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

USER: My travelling dates are Sep 07 and Sep 09.

ASSISTANT: Can I know your airport codes too?

USER: My airport codes are DCA and SEA.

ASSISTANT: Do you need any specifications?

USER: I want to depart on afternoon and return on morning.

ASSISTANT: Sorry, there are no flights found.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.