You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Margaret Lee.

ASSISTANT: Margaret, what kind of help are you expecting from my side?

USER: I would like to book a flight ticket from IAD to SFO. Could you please help me out?

ASSISTANT: Sure, can I know your itinerary dates?

USER: I am planning to start on 07/18 and return back on 07/20.

ASSISTANT: I found a flight 1018 of UA airlines matches with your preferences, can I proceed?

USER: Yes, please proceed with the booking.

ASSISTANT: Your ticket is booked.

USER: Thank you for the help.

ASSISTANT: Thank you, have a great day ahead.