You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me in booking a flight ticket from DCA to BOS?

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

USER: I want to travel on 04/29, and return on 05/01.

ASSISTANT: Do you have any other requirements?

USER: I need a direct flight.

ASSISTANT: Can I know your name please?

USER: I am Deborah Smith.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Most welcome.