javascript 设置密码强弱

table tr td style="width: 201px; height: 22px;" valign="middle" align="right" 登录密码：bfont color="red"*/font/b /td td align="left" style="height: 22px" input name="txtregistpwd1" type="password" id="txtregistpwd1" class="wenbenkuang" on

登录密码：*
密码强弱：	弱 中 强

// JavaScript Document
// 测试某个字符是属于哪一类
function CharMode(iN)
{
if (iN >= 48 && iN return 1;
if (iN >= 65 && iN return 2;
if (iN >= 97 && iN 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 {
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 return 0;
// 密码太短
Modes = 0;
for (i = 0; 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 = "#cccccc";
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 = O_color;
Mcolor = M_color;
Hcolor = O_color;
break;
default :
Lcolor = O_color;
Mcolor = O_color;
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;
}