//显示颜色  
function pwStrength(pwd) {
    O_color = "#eeeeee";
    L_color = "#ffd8b4";
    M_color = "#ffaf56";
    H_color = "#e85959";
    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 = L_color;
                Mcolor = M_color;
                Hcolor = O_color;
                break;
            default:
                Lcolor = L_color;
                Mcolor = M_color;
                Hcolor = H_color;
        }
    }
    $("#strength_L").css('background-color', Lcolor);
    $("#strength_M").css('background-color', Mcolor);
    $("#strength_H").css('background-color', Hcolor);
    return;
}

//判断输入密码的类型  
function CharMode(iN) {
    if (iN >= 48 && iN <= 57) //数字  
        return 1;
    if (iN >= 65 && iN <= 90) //大写  
        return 2;
    if (iN >= 97 && iN <= 122) //小写  
        return 4;
    else return 8;
}
//bitTotal函数  
//计算密码模式  
function bitTotal(num) {
    modes = 0;
    for (i = 0; i < 4; i++) {
        if (num & 1) modes++;
        num >>>= 1;
    }
    return modes;
}
//返回强度级别  
function checkStrong(sPW) {
    if (sPW.length <= 4) return 0; //密码太短  
    Modes = 0;
    for (i = 0; i < sPW.length; i++) {
        //密码模式  
        Modes |= CharMode(sPW.charCodeAt(i));
    }
    return bitTotal(Modes);
}
