<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" style='display:inline'>
<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>
