You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I would like to make a flight ticket reservation form IAD to LAS, can you please help me?

ASSISTANT: Yes, can you tell me your dates of travel?

USER: Sure, my planned travelling dates are Dec, 21 and 23 respectively.

ASSISTANT: Do you have any other preferences?

USER: Flight has to be with single connection.

ASSISTANT: Give me a moment.

USER: Sure, I will wait.

ASSISTANT: I have found an economy class ticket with a price of 200 and 1 connection.

USER: Please proceed for booking.

ASSISTANT: Can I know your name for booking?

USER: Sure, my name is William Lopez here.

ASSISTANT: Your ticket has been booked.

USER: Thank you for your service.

ASSISTANT: Thank you for contacting us.