function chkpwd(obj){
		var t=obj.value;
		var id=getResult(t);
		
		//定义对应的消息提示
		var msg=new Array(4);
		msg[0]="密码过短。";
		msg[1]="密码强度差。";
		msg[2]="密码强度良好。";
		msg[3]="密码强度高。";
		
		var sty=new Array(4);
		sty[0]=-45;
		sty[1]=-30;
		sty[2]=-15;
		sty[3]=0;
		
		var col=new Array(4);
		col[0]="gray";
		col[1]="red";
		col[2]="#ff6600";
		col[3]="Green";
		
		//设置显示效果
		var bImg="images/other/pwdlen.gif";//一张显示用的图片
		var sWidth=300;
		var sHeight=15;
		var Bobj=document.getElementById("chkResult");

		Bobj.style.fontSize="12px";
		Bobj.style.color=col[id];
		Bobj.style.width=sWidth + "px";
		Bobj.style.height=sHeight + "px";
		Bobj.style.lineHeight=sHeight + "px";
		Bobj.style.background="url(" + bImg + ") no-repeat left " + sty[id] + "px";
		Bobj.style.textIndent="20px";
		Bobj.innerHTML="检测提示：" + msg[id];
	}
	
	//定义检测函数,返回0/1/2/3分别代表无效/差/一般/强
	function getResult(s){
		if(s.length < 4){
			return 0;
		}
		var ls = 0;
		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--;
		}
		return ls
	}