密码强度

<script type="text/javascript">
        $('#newpassword').click(function () {
            $('#pwdTip').show();
        });
        //测试某个字符是属于哪一类.      
        function CharMode(iN) {
            if (iN >= 48 && iN <= 57) //数字      
                return 1;
            if (iN >= 65 && iN <= 90) //大写字母      
                return 2;
            if (iN >= 97 && iN <= 122) //小写      
                return 2;
            else
                return 8; //特殊字符      
        }
        //计算出当前密码当中一共有多少种模式      
        function bitTotal(num) {
            modes = 0;
            for (i = 0; i < 4; i++) {
                if (num & 1) modes++;
                num >>>= 1;
            }
            return modes;
        }
        //密码强度判断
        function checkStrong(sPW) {
            if (sPW.length <= 6) {
                return 0; //密码太短  
            }
            if (sPW.length == 6) {
                return 1; //密码太短  
            }
            Modes = 0;
            for (i = 0; i < sPW.length; i++) {
                //测试每一个字符的类别并统计一共有多少种模式.      
                Modes |= CharMode(sPW.charCodeAt(i));
            }
            var modes = bitTotal(Modes);
            if (modes == 1) {
                return 1;
            }
            if (modes == 2) {
                if (sPW.length >= 7 && sPW.length <= 16) {
                    return 2;
                }
            }
            if (modes == 3) {
                if (sPW.length == 7 || sPW.length == 8) {
                    return 2;
                }
                if (sPW.length >= 9 && sPW.length <= 16) {
                    return 5;
                }
            }
        }
        //当用户放开键盘或密码输入框失去焦点时,根据不同的级别显示不同的颜色
        function pwdStrength(pwd) {
            O_color = "";
            //L_color = "week";
            //M_color = "normal";
            //H_color = "strong";
            L_color = "strength-l";
            M_color = "strength-m";
            H_color = "strength-r";
            M_color0 = "normal0";
            H_color0 = "strong0";
            if (pwd == null || pwd == '') {
                Lcolor = Mcolor = Hcolor = O_color;
            }
            else {
                S_level = checkStrong(pwd);
                switch (S_level) {
                    case 0:
                        Lcolor = Mcolor = Hcolor = O_color;
                    case 1:
                        Lcolor = L_color;
                        Mcolor = Hcolor = O_color;
                        break;
                    case 2:
                        Lcolor = M_color0;
                        Mcolor = M_color;
                        Hcolor = O_color;
                        break;
                    default:
                        Lcolor = Mcolor = H_color0;
                        Hcolor = H_color;
                        break;
                }
            }
            $("#strength_L").attr('class', Lcolor);
            $("#strength_M").attr('class', Mcolor);
            $("#strength_H").attr('class', Hcolor);
            return;
        }
    </script>