You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: I want to book a flight ticket from DCA to IAD, can you please help me?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: My journey dates are Apr 3 and Apr 5.

ASSISTANT: Do you have any connection limit preference?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any other specifications for this trip?

USER: No, other preferences.

ASSISTANT: May I know your good name please?

USER: Myself Kenneth Phillips.

ASSISTANT: Kenneth Phillips, there are no flight services are available on this route on your provided dates.

USER: No issue, anyway thank you for checking.

ASSISTANT: Thank you for contacting us.