FF mouseleave/mouseenter事件

Question

我写了FF的扩展，这部分代码在早期版本6.0-8.0上不起作用。但在12.0-13.0版本中，一切都运行得很好。原因何在？

        for(var i = 0; i < doc.getElementsByClassName('repInfo').length; i++)
        {
            doc.getElementsByClassName('repInfo')[i].getElementsByTagName('a')[0].style.visibility = "hidden";
            doc.getElementsByClassName('repInfo')[i].getElementsByTagName('a')[1].style.visibility = "hidden";

            doc.getElementsByClassName('repInfo')[i].addEventListener('mouseleave', 
                function(e) {
                    e.target.getElementsByTagName('a')[0].style.visibility = "hidden";
                    e.target.getElementsByTagName('a')[1].style.visibility = "hidden";
                }, false);
            doc.getElementsByClassName('repInfo')[i].addEventListener('mouseenter', 
                function(e) { 
                    e.target.getElementsByTagName('a')[0].style.visibility = "visible";
                    e.target.getElementsByTagName('a')[1].style.visibility = "visible";
                }, false);
        }

Answer 1

Firefox10增加了对mouseenter和mouseleave的支持。