引用地址：http://www.klstudio.com/post/90.html
JavaScript实现密码强度检测，已经提供了方法，实现非常简单。
HTML代码如下：
<html>
<head>
<title>PasswordStrength</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script language="javascript" src="js/passwordstrength.js"></script>
</head>
<body>
<h4>密码强度检测</h4>
<table width="100%" border="0" cellspacing="1" cellpadding="0">
<tr>
<td width="100" align="right">强度显示：</td>
<td>
<script language="javascript">
var ps = new PasswordStrength();
ps.setSize("200","20");
ps.setMinLength(5);
</script>
</td>
</tr>
<tr>
<td align="right">密码检测：</td>
<td><input name="pwd" type="password" id="pwd" style="200px" onKeyUp="ps.update(this.value);"></td>
</tr>
</table>
</body>
</html>
<head>
<title>PasswordStrength</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script language="javascript" src="js/passwordstrength.js"></script>
</head>
<body>
<h4>密码强度检测</h4>
<table width="100%" border="0" cellspacing="1" cellpadding="0">
<tr>
<td width="100" align="right">强度显示：</td>
<td>
<script language="javascript">
var ps = new PasswordStrength();
ps.setSize("200","20");
ps.setMinLength(5);
</script>
</td>
</tr>
<tr>
<td align="right">密码检测：</td>
<td><input name="pwd" type="password" id="pwd" style="200px" onKeyUp="ps.update(this.value);"></td>
</tr>
</table>
</body>
</html>