密码强度的js插件（完成）

效果如下图：

低：

中：

高：

页面上需要绑定的id如下：

 <div class="passwordtishi f12">
                    <font class="c666">安全程度：</font>
                    <span id="strength_L">弱</span><span id="strength_M">中</span><span id="strength_H">强</span>
                </div>

引用的js如下：

//密码强度弱中强变色js

//CharMode函数
//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 4;
    else
        return 8; //特殊字符
}
//bitTotal函数
//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;
}
//checkStrong函数
//返回密码的强度级别
function checkStrong(sPW) {
    if (sPW.length <= 4)
        return 0; //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));
    }
    return bitTotal(Modes);
}
//pwStrength函数
//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 pwStrength(pwd) {
    O_color = "#eeeeee";
    L_color = "#FF0000";
    M_color = "#FF9900";
    H_color = "#33CC00";
    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 = Mcolor = M_color;
                Hcolor = O_color;
                break;
            default:
                Lcolor = Mcolor = Hcolor = H_color;
        }
    }
    document.getElementById("strength_L").style.background = Lcolor;
    document.getElementById("strength_M").style.background = Mcolor;
    document.getElementById("strength_H").style.background = Hcolor;
    return;
}