You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you help me to book a flight ticket within the range of 500?

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

USER: Charlotte, NC - CLT is my source and Washington, DC - IAD is my destination.

ASSISTANT: Could you please share your travel dates?

USER: 04/27 and 04/29 are my travelling dates.

ASSISTANT: May I know your name please?

USER: Sarah Lewis is my name.

ASSISTANT: We found a Southwest airline, flight number: 1014, price: 200 with one connection.

USER: Please proceed for booking.

ASSISTANT: Your flight ticket has been confirmed.

USER: Thanks for booking my ticket.

ASSISTANT: Thank you for opting us.