You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my reservation, can you please do that for me?

ASSISTANT: I will change to reservation if I find the reservation you did. Please wait a moment.

USER: Thank you, my name is Joshua Campbell.

ASSISTANT: Yes, the reservation has been found. May I know your travel dates to change?

USER: Sure, I want to depart on 12/29 and return back on 12/31.

ASSISTANT: Ok, the airport codes is necessary to amend the reservation. Can I know?

USER: Sure, I will travel from PHX to ATL.

ASSISTANT: There is a flight available with 1 connection limit and the airfare is 600. Can I book?

USER: No, please check for the flight which has the airfare of 500.

ASSISTANT: Sorry Campbell, there are no flight available with that budget you had provided.

USER: Not an issue, thank you for checking.

ASSISTANT: Ok, thank you for connecting with our agency.