ItemRollOver-event of a listbox

Hi there, I’m new here, hope you can help.

I’m using this code trying to get the item ‘rolled-over’ in a listbox.
But it don’t work. My ‘Output window’ stays blank.

on (itemRollOver) {
form.itemRollOver = function (eventObj) {
trace(“Item #” + eventObj.index + " has been rolled over.");
listbox.addEventListener(“itemRollOver”, form);

What’s wrong here?
Is there a good tutorial about the use of components in FMX 2004?

Thanks en greetz,
Athlon 1400.