This property returns the target of the event. When we trigger an event and create
an event object, we assign a box as the target of this event. This target is the
point that we start bubbling up the event. When the event is bubbling up, the target
of the event might be changed (for example, the targetBox of a mouse-related event
might be changed based on the preventDefault attribute setting).
var targetBox = eventObj.targetBox;
if (targetBox)
{
targetBox.setStyle("someStyle", "someValue");
}