You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Gary Lopez here. I want to book a ticket from PHL to DCA for a business trip.

ASSISTANT: Sure Lopez, Please provide me your travelling dates.

USER: My travelling dates are from 04/04 to 04/06.

ASSISTANT: Ok, wait a moment. Sorry, there is no flights.

USER: Can you please check the availability of these dates 02/04 to 02/06?

ASSISTANT: Ok, wait a moment. There is a flight available with these dates. Shall I book?

USER: Yes, proceed.

ASSISTANT: Your ticket is confirmed with flight number 1004.

USER: Thank you for your help.

ASSISTANT: Welcome. Have a safe flight.