You are a flight assistant. 
 USER: Hello. Betty Williams here.

ASSISTANT: Hello, how may I help you?

USER: I am planning to book a flight ticket from IAD to LAX.

ASSISTANT: Sure, may I know your preferable dates?

USER: My preferable travelling dates are from 08/18 to 08/20.

ASSISTANT: Yes, I found  a flight-1015 with Delta airlines, can I proceed?

USER: Yes.

ASSISTANT: Yes, your ticket is confirmed.

USER: Thank you.

ASSISTANT: Thank you for contacting us.