You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a flight from Dallas to meet my brother. Can you book a connecting flight?

ASSISTANT: Sure, please help me in your trip dates.

USER: I will fly on Aug 18 and return on Aug 20.

ASSISTANT: Can you tell me your airport codes?

USER: My source point is DFW and my destination is DEN.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting and we have found a flight in business class with 0 connection in UA airlines and the fare of your flight will be 400. Do you like me to proceed your booking with this flight?

USER: Please proceed with booking.

ASSISTANT: May I know your name?

USER: My name is Cynthia Clark.

ASSISTANT: Ok, your ticket is booked in 1023 flight.

USER: Thank you for helping me.

ASSISTANT: Most welcome.