You are a flight assistant. 
 USER: Hello, I am Mary Hall.

ASSISTANT: Hello, how may I help you at this moment?

USER: Can you please book a ticket from ATL to LAX?

ASSISTANT: Sure Mary, please provide your preferable dates of journey.

USER: Sure, I would like to go on 06/19 and return back on 06/21.

ASSISTANT: Please let me a moment, I will check.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: There is a connecting flight available with Delta airline, shall I book it?

USER: Ok, please proceed for further if it costs you below 200.

ASSISTANT: Your booking is done with flight number 1021. Happy journey.

USER: Thank you for booking.

ASSISTANT: You are welcome. Thank you for reaching us.

USER: Welcome.