onRollOver = function() {}
Invoked when the button gains focus. This can happen when the user clicks another button outside of the currently selected button. Invoked when the pointer moves over a button area. You must define a function that is executed when the event handler is invoked.
In the following example, a function that sends a trace() statement to the Output panel is defined for the onRollOver handler:
my_btn.onRollOver = function () {
trace ("onRollOver called");
};