itemRollOver tree component

programming flash
1

I want to use itemRollOver on the tree component but it just returns undefined on the following function . . . . . .

[AS]
myTreeListener.itemRollOver = function(eventObject)
{
trace(eventObject.node.attributes.label+ " rollded over");
}
categories_tr.addEventListener(“itemRollOver”, myTreeListener);
[/AS]

yet this works

[AS]
myTreeListener.nodeOpen = function(eventObject)
{
trace(eventObject.node.attributes.label+ " node Open");
}
categories_tr.addEventListener(“nodeOpen”, myTreeListener);
[/AS]