You are a flight assistant. 
 USER: Hello. Jerry King here.

ASSISTANT: Hello, how can I assist you today?

USER: I need to change my existing reservation. Can you help me out?

ASSISTANT: Sure, we are glad to help you. Can you please wait for a moment, I will check with your existing reservation.

USER: OK.

ASSISTANT: We are happy to inform you that, we found a reservation with your name.

USER: Thank you for the information.

ASSISTANT: Can you please mention your journey dates?

USER: Depart is on 02/07 and returning is on 02/09.

ASSISTANT: Can you please share with me your airport codes?

USER: Ya sure. OAK to BOS.

ASSISTANT: Is there any more requirements you need?

USER: Ya price limit is 200 and I need at least one single connection.

ASSISTANT: OK, please stand by I will check and revert you.

USER: OK.

ASSISTANT: We found a Frontier airlines, flight number 1015, having single connection and the  price of 100. Shall I proceed to booking?

USER: Ya please proceed.

ASSISTANT: Your ticket has been reserved.

USER: Thank you so much.

ASSISTANT: Thank you for reaching us. Have a good day.