You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I would like to attend my friend birthday at Washington, can you please book me a ticket?

ASSISTANT: Sure, please provide your airport codes.

USER: My airport codes are from DEN to IAD.

ASSISTANT: When are you planning to travel?

USER: I would like to leave between 12/20 and 12/22.

ASSISTANT: Hawaiian airlines with single connection and price is 100 of 1015 flight. Shall I proceed for booking?

USER: Yes, you can.

ASSISTANT: May I know your name?

USER: My name is Raymond Hill.

ASSISTANT: Your ticket has been confirmed.

USER: Thanks for your help.

ASSISTANT: Thank you.