捕获浏览器的前进、后退事件 window.onhashchange 并区别于点击链接

<html>　　　
    
    <head>　　　
        <meta http-equiv="content-type" content="text/html;charset=utf-8">　　　
        <title>onhashchange测试</title></head>　　　
    
    <body>
            <a href="#p2">p2</a>
    <script>
       document.onmouseover = function() {
            //User's mouse is inside the page.
            window.innerDocClick = true;
        }

        document.onmouseleave = function() {
            //User's mouse has left the page.
            window.innerDocClick = false;
        }

        window.onhashchange = function() {
            if (window.innerDocClick) {
                //Your own in-page mechanism triggered the hash change
                alert('You click a link');
            } else {
                //Browser back button was clicked
                alert('You click browser button');
            }
        }　　　</script>　　　
</html>