You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I would like to change my reservation due to postponed of my exam, so please help me in changing.

ASSISTANT: Sure, may I know your name?

USER: Sure, I am Patrick Davis.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, we found a reservation on your name. Can you please share your travelling dates?

USER: Sure, my travelling dates are on Sept 1st to 3rd.

ASSISTANT: Please share your airport codes.

USER: My airport codes are JFK - LAX.

ASSISTANT: May I know your connection limit?

USER: I need a single connection.

ASSISTANT: Sorry, there are no flights found based on your details.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.