You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am William Lewis. I would like to visit Washington DC as there is a famous tourist place to visit. Will you please book a flight ticket?

ASSISTANT: Good to hear that. Sure, I can help you with that. William, can you please help me with your travelling dates?

USER: Sure, my travelling dates are 06/14 and 06/16.

ASSISTANT: Could you please provide the source and the destination airport codes?

USER: Sure, Airport codes are SFO and IAD.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Ok, please take a time.

ASSISTANT: William, there is a flight available at your request with price 100. Would you like me to proceed the booking?

USER: Yes, please book it.

ASSISTANT: Sure. Your booking is confirmed.Your flight number is 1028 with Spirit airline.

USER: Thank you for your help.

ASSISTANT: Have a great day. You are welcome. Thank you for contacting us.