[Sortables] What does this demo function do?

[Sortables] What does this demo function do?


Hi,
I am new to jQuery UI. I was looking through the demos and I found
this: http://ui.jquery.com/repository/real-world/layout/
Can someone explain to me what the updateUpDown() function does?
(http://ui.jquery.com/repository/real-world/layout/demo.js)
Thanks,
Jeff