You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I am Samuel Turner, please book a flight ticket for a round trip from LAS.

ASSISTANT: Sure, when are you planning to travel?

USER: My travelling dates are Feb, 12 and Feb, 14.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: How much can you afford for this booking?

USER: I can afford up to 500.

ASSISTANT: Ok, there is an UA airline with flight number 1001 is going on your way and the fare is 100. Is that fine?

USER: It's fine, please proceed.

ASSISTANT: Your booking has been confirmed.

USER: Thank you.

ASSISTANT: Thank you for opting us.