You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Richard Turner and I want to book a ticket. Will you please help me?

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: Yes,I want to travel from. DTW to IAD.

ASSISTANT: OK, may I know your journey dates?

USER: My preferable dates are 07/21 and 07/23.

ASSISTANT: Is there any restrictions in price and connections?

USER: Yes,please notice that the flight should be with single connection and the price should be with in 500.

ASSISTANT: Give me a moment to check.

USER: Sure.

ASSISTANT: I have found a flight as per your request.

USER: OK,can I know the flight details.

ASSISTANT: Flight number is 1020 from Hawaiian airline. Shall I confirm your ticket?

USER: OK,please confirm this ticket for me.

ASSISTANT: Your ticket has booked.

USER: Thank you.

ASSISTANT: Thanking for choosing our service, have a great journey.