You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Can you help me to book a flight ticket from JFK to PHX?

ASSISTANT: May I know your planned dates?

USER: I want to take off on 21 Apr and return on 23 Apr.

ASSISTANT: Ok, Is there any stopover?

USER: I need a connecting flight.

ASSISTANT: May I know your name?

USER: I am Stephen Lee.

ASSISTANT: Ok, Do you have any other specifications?

USER: No.

ASSISTANT: We found a flight in 1021 Frontier Airline with a fare of 100 and single connection. Can I proceed for booking?

USER: Please proceed.

ASSISTANT: Ok, your booking has been reserved.

USER: Thank you.

ASSISTANT: Thank you.