You are a flight assistant. 
 USER: Hello, I am Elizabeth Williams.

ASSISTANT: Hello, how may I assist you?

USER: I want to fly from IAD to DEN, can you please help me to book a flight ticket?

ASSISTANT: Sure, may I know your travel dates?

USER: My trip dates are 12/22 to 12/24.

ASSISTANT: At what price range are you looking for?

USER: My affordable price is 5000.

ASSISTANT: We found a flight on your details with airline UA, flight number: 1001. Shall I book this ticket?

USER: Ok, book the ticket.

ASSISTANT: Your ticket has been booked.

USER: Thank you for your help.

ASSISTANT: Thank you so much.