function CharMode(iN){  
if (iN>=48 && iN <=57)   
return 1;  
if (iN>=65 && iN <=90)   
return 2;  
if (iN>=97 && iN <=122)   
return 4;  
else  
return 8;   
}  
 
function bitTotal(num){  
modes=0;  
for (i=0;i<4;i++){  
if (num & 1) modes++;  
num>>>=1;  
}  
return modes;  
}  
 
function checkStrong(sPW){  
if (sPW.length<=4)  
return 0;   
Modes=0;  
for (i=0;i<sPW.length;i++){   
Modes|=CharMode(sPW.charCodeAt(i));  
}  
return bitTotal(Modes);  
}  
  
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;  
}