jQuery判断密码强度

<head>

    <title></title>
    <script src="jquery-1.9.1.js" type="text/javascript"></script>
    <style type="text/css">
    .qiang{background:url(/images/pas4.JPG) no-repeat;width:150px;height:40px;float:left;}
    .zhong{background:url(/images/pas3.JPG) no-repeat;width:150px;height:40px;float:left;}
    .ruo{background:url(/images/pas2.JPG) no-repeat;width:150px;height:40px;float:left;}
    .ruox{background:url(/images/pas1.JPG) no-repeat;width:150px;height:40px;float:left;}
    .div1css{float:left;width:200px;}
    </style>
    <script type="text/javascript">
        $(function () {
            $('#pass').keyup(function () {
                var strongRegex = new RegExp("^(?=.{8,})(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])(?=.*\\W).*$", "g");
                var mediumRegex = new RegExp("^(?=.{7,})(((?=.*[A-Z])(?=.*[a-z]))|((?=.*[A-Z])(?=.*[0-9]))|((?=.*[a-z])(?=.*[0-9]))).*$", "g");
                var enoughRegex = new RegExp("(?=.{6,}).*", "g");

                if (false == enoughRegex.test($(this).val())) {
                    $('#div2').addClass('ruox');
                    //$('#passstrength').html('小于六位的时候'); //密码小于六位的时候，密码强度图片都为灰色
                }
                 else if (strongRegex.test($(this).val())) {
                     $('#div2').removeClass('zhong');
                    $('#div2').addClass('qiang');
                    //$('#passstrength').html('强!'); //密码为八位及以上并且字母数字特殊字符三项都包括
                }
                else if (mediumRegex.test($(this).val())) {
                    $('#div2').removeClass('ruo');
                    $('#div2').addClass('zhong');
                    //$('#passstrength').html('中!'); //密码为七位及以上并且字母、数字、特殊字符三项中有两项，强度是中等
                }
                 else {
                     $('#div2').removeClass('ruox');
                    $('#div2').addClass('ruo');
                    //$('#passstrength').html('弱!');   //如果密码为6为及以下，就算字母、数字、特殊字符三项都包括，强度也是弱的
                }
                return true;
            });
        })
    </script>
</head>
<body>
<div id="div1" class="div1css">
<input type="password" name="pass" id="pass" /></div>
<div id="div2"><span id="passstrength"></span></div>
</body>

补充：web前端 , JavaScript ,