You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you?

USER: I am Debra Lewis. I want to book a ticket from PHL to IAD to attend seminar, can you help me in booking?

ASSISTANT: Sure, can I know your preferable dates?

USER: I am departing on 09/21 and return on 09/23.

ASSISTANT: I found a flight 1000 of Delta airlines matches with your preferences, can I proceed?

USER: Please proceed for booking.

ASSISTANT: Your ticket is booked.

USER: Thank you for your help.

ASSISTANT: Thank you, have a good day.