JavaScriptパスワード強度検証

<script type="text/javascript"> 
var $ = function(v){return document.getElementById(v);} 
function isSecurity(v){ 
 if (v.length < 3) { iss.reset();return;} 
 var lv = -1; 
 if (v.match(/[a-z]/ig)){lv++;} 
 if (v.match(/[0-9]/ig)){lv++;} 
 if (v.match(/(.[^a-z0-9])/ig)){lv++;} 
 if (v.length < 6 && lv > 0){lv--;} 
 iss.reset(); 
 switch(lv) {  
 case 0: 
 iss.level0(); 
 break; 
 case 1: 
 iss.level1(); 
 break; 
 case 2: 
 iss.level2(); 
 break; 
 default: 
 iss.reset(); 
 } 
} 
var iss = { 
 color:["CC0000","FFCC33","66CC00","CCCCCC"], 
 text:[" "," "," "], 
 width:["50","100","150","10"], 
 reset:function(){ 
 $("B").style.backgroundColor = iss.color[3]; 
 $("B").style.width = iss.width[3]; 
 $("A").innerHTML = ""; 
 }, 
 level0:function(){ 
 $("B").style.backgroundColor = iss.color[0]; 
 $("B").style.width = iss.width[0]; 
 $("A").innerHTML = "    ";  
 }, 
 level1:function(){ 
 $("B").style.backgroundColor = iss.color[1]; 
 $("B").style.width = iss.width[1]; 
 $("A").innerHTML = " ";  
 }, 
 level2:function(){ 
 $("B").style.backgroundColor = iss.color[2]; 
 $("B").style.width = iss.width[2]; 
 $("A").innerHTML = "  "; 
 } 
} 
</script>
<table border="0" style="border-collapse:collapse;">
	<tr>
		<td>  :<input type="password" size=50 maxlength=20 onkeyup="isSecurity(this.value);"></td>
		<td bgcolor="#EEEEEE" id="B"></td>
		<td id="A">      </td>
	</tr>
</table>