function PasswordStrength(showed){ 
this.showed = (typeof(showed) == "boolean")?showed:true;
this.styles = new Array(); 
this.styles[0] = {backgroundColor:"#EBEBEB",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #BEBEBE",borderBottom:"solid 1px #BEBEBE"}; 
this.styles[1] = {backgroundColor:"#FF4545",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #BB2B2B",borderBottom:"solid 1px #BB2B2B"};
this.styles[2] = {backgroundColor:"#FFD35E",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #E9AE10",borderBottom:"solid 1px #E9AE10"};
this.styles[3] = {backgroundColor:"#95EB81",borderLeft:"solid 1px #FFFFFF",borderRight:"solid 1px #3BBC1B",borderBottom:"solid 1px #3BBC1B"};

this.labels= ["弱","中","强"];

this.divName = "pwd_div_"+Math.ceil(Math.random()*100000);
this.minLen = 6;

this.width = "181px";
this.height = "16px";

this.content = "";

this.selectedIndex = 0;

this.init(); 
}
PasswordStrength.prototype.init = function(){
var s = '<table cellpadding="0" id="'+this.divName+'_table" cellspacing="0" style="width:'+this.width+';height:'+this.height+';">';
s += '<tr>';
for(var i=0;i<3;i++){
    s += '<td id="'+this.divName+'_td_'+i+'" width="33%" align="center"><span style="font-size:1px">&nbsp;</span><span id="'+this.divName+'_label_'+i+'" style="display:none;font-family: Courier New, Courier, mono;font-size: 12px;color: #000000;">'+this.labels[i]+'</span></td>';
} 
s += '</tr>';
s += '</table>';
this.content = s;
if(this.showed){
    document.write(s);
    this.copyToStyle(this.selectedIndex);
} 
}
PasswordStrength.prototype.copyToObject = function(o1,o2){
for(var i in o1){
    o2[i] = o1[i];
}
}
PasswordStrength.prototype.copyToStyle = function(id){
this.selectedIndex = id;
for(var i=0;i<3;i++){
    if(i == id-1){
     this.$(this.divName+"_label_"+i).style.display = "inline";
    }else{
     this.$(this.divName+"_label_"+i).style.display = "none";
    }
}
for(var i=0;i<id;i++){
    this.copyToObject(this.styles[id],this.$(this.divName+"_td_"+i).style);   
}
for(;i<3;i++){
    this.copyToObject(this.styles[0],this.$(this.divName+"_td_"+i).style);
}
}
PasswordStrength.prototype.$ = function(s){
return document.getElementById(s);
}
PasswordStrength.prototype.setSize = function(w,h){
this.width = w;
this.height = h;
}
PasswordStrength.prototype.setMinLength = function(n){
if(isNaN(n)){
    return ;
}
n = Number(n);
if(n>1){
    this.minLength = n;
}
}
PasswordStrength.prototype.setStyles = function(){
if(arguments.length == 0){
    return ;
}
for(var i=0;i<arguments.length && i < 4;i++){
    this.styles[i] = arguments[i];
}
this.copyToStyle(this.selectedIndex);
}
PasswordStrength.prototype.write = function(s){
if(this.showed){
    return ;
}
var n = (s == 'string') ? this.$(s) : s;
if(typeof(n) != "object"){
    return ;
}
n.innerHTML = this.content;
this.copyToStyle(this.selectedIndex);
}
PasswordStrength.prototype.update = function(s){
if(s.length < this.minLen){
    this.copyToStyle(0);
    return;
}
var ls = -1;
if (s.match(/[a-z]/ig)){
    ls++;
}
if (s.match(/[0-9]/ig)){
    ls++;
}
    if (s.match(/(.[^a-z0-9])/ig)){
    ls++;
}
if (s.length < 6 && ls > 0){
    ls--;
}
    switch(ls) { 
     case 0:
      this.copyToStyle(1);
      break;
     case 1:
      this.copyToStyle(2);
      break;
     case 2:
      this.copyToStyle(3);
      break;
     default:
      this.copyToStyle(0);
    }
}