<script language=javascript>

//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;

}

</script>

<form name=form1 action="" >

输入密码:

<input type=password size=10 onKeyUp=pwStrength(this.value)

onBlur=pwStrength(this.value)>

<br>密码强度:

<table width="217" border="1" cellspacing="0" cellpadding="1" bordercolor="#cccccc"

height="23">

<tr align="center" bgcolor="#eeeeee">

<td width="33%" id="strength_L">弱</td>

<td width="33%" id="strength_M">中</td>

<td width="33%" id="strength_H">强</td>

</tr>

</table>

</form>