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

ASSISTANT: Hello, how can I amend you today?

USER: Can you change my existing reservation due to my health issue?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, there is a reservation found on your name.

USER: Ok.

ASSISTANT: Please share your new journey details.

USER: My travelling dates are from 12/26 to 12/28. My airport codes are from AUS to MSP.

ASSISTANT: Thank you for the details.

USER: Ok.

ASSISTANT: I am glad to inform you that, there is a flight available with Delta airline, flight number 1024 with fare 100 and a lay by.

USER: Ok, Proceed.

ASSISTANT: Your reservation has been successfully changed.

USER: Thank you.

ASSISTANT: Thank you for contacting us.