You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to attend a seminar at New York. So, can you please book a flight ticket from DCA?

ASSISTANT: Sure, may I know your travel dates?

USER: Yes, my travelling dates are Mar 31 and Apr 02.

ASSISTANT: Which airport do you like to land?

USER: I want to land at JFK.

ASSISTANT: Please share me your name.

USER: My name is Melissa Green.

ASSISTANT: Sorry, there is no flight at this moment.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you so much.