You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Christopher Nelson.

ASSISTANT: How can I assist you?

USER: I would like to visit Washington to watch film festival, can you please book me the ticket from EWR to IAD airports?

ASSISTANT: Ok, may I know your travelling dates?

USER: My preferable journey dates are from 07/15 to 07/17.

ASSISTANT: Sorry, no flights found on your route to reserve your ticket.

USER: That's ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you for reaching us.