You are a flight assistant. 
 USER: Hello. I am Robert Williams.

ASSISTANT: Hello, how can I be your helping hand?

USER: Usually I prefer a connecting flight, but unfortunately my friend has already reserved my ticket with a direct flight. So, I want to change it. Can you help me?

ASSISTANT: Sure. Please wait for a moment, I will check your previous reservation.

USER: Sure.

ASSISTANT: Thank you for being patience, there is a reservaton found on your name.

USER: Ok.

ASSISTANT: Please, share your new travelling dates.

USER: Journey dates are 08/20 to 08/22.

ASSISTANT: Can I have your boarding and landing airport codes please?

USER: Airport codes are SEA to IAH.

ASSISTANT: Thank you for your time, there is a flight available in Spirit airline, flight number 1000 having fare 100 and a lay by. Can I proceed to change?

USER: Yes, you can.

ASSISTANT: Your reservation has been successfully changed.

USER: Thank you.

ASSISTANT: Thank you for reaching us.