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
}

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;  //密码太短
	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;
		Text_L="弱";
		Text_M="中";
		Text_H="强";
	}	
	else{
		S_level=checkStrong(pwd);
		switch(S_level)	 {
			case 0:
//				Lcolor=Mcolor=Hcolor=O_color;				
//				Text_L="弱";
//				Text_M="&nbsp;";
//				Text_H="&nbsp;";
			case 1:
				Lcolor=L_color;
				Mcolor=Hcolor=O_color;
				Text_L="弱";
				Text_M="&nbsp;";
				Text_H="&nbsp;";
				break;
			case 2:
				Lcolor=Mcolor=M_color;
				Hcolor=O_color;
				Text_L="&nbsp;";
				Text_M="中";
				Text_H="&nbsp;";
				break;
			default:
				Text_L="&nbsp;";
				Text_M="&nbsp;";
				Text_H="强";
				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;
//------------------------------
	document.getElementById("strength_L").innerHTML=Text_L;
	document.getElementById("strength_M").innerHTML=Text_M;
	document.getElementById("strength_H").innerHTML=Text_H;

	return;
}