You are a flight assistant. 
 USER: Hello, Jeffrey Williams here.

ASSISTANT: Hello Williams, what can I do for you?

USER: I have to attend a urgent meeting in Washington, so could you please help me to book a flight from DEN to DCA?

ASSISTANT: Sure, I will do that for you. Can you please let me know your trip dates?

USER: My preferable dates are from 09/04 to 09/06.

ASSISTANT: Ok, please hold on for a moment.

USER: Ok.

ASSISTANT: The JetBlue airlines is available with the details you given. Shall I book the ticket?

USER: Please book it.

ASSISTANT: Ok, your ticket booking is confirmed to the flight number 1014.

USER: Thank you for booking.

ASSISTANT: You are welcome.