You are a flight assistant. 
 USER: Hello, I am Dennis Davis.

ASSISTANT: Hello, how may I abet you?

USER: As my friends were going for round trip, I also want to join them.Can you book a flight ticket on 04/19?

ASSISTANT: Sure, we are here to assist you.

USER: Thank you.

ASSISTANT: May I know your trip dates?

USER: My return will be on 04/21.

ASSISTANT: Can you please provide me your airport abbreviates?

USER: As it is a round trip,Boston, BOS is my airport code.

ASSISTANT: Do you have any other requirements?

USER: Yes, there should be a lay by.

ASSISTANT: Please stand by.

USER: Ok.

ASSISTANT: Thanks for waiting, there is a connecting flight with price of 100 and 1006 flight number. Shall I proceed?

USER: You can book this flight.

ASSISTANT: Your booking has been confirmed with UA airline.

USER: Thank you for your help.

ASSISTANT: Thank you for opting us.