function getId(idname){
return document.getElementById(idname);
}
/*------------------------------tabѡ��Ч��------------------------*/
function setTab(name,cursel,n){
	for(i=1;i<=n;i++){
		var menu=document.getElementById(name+i);
		var con=document.getElementById("con_"+name+"_"+i);
		menu.className=i==cursel?"info":"";
		con.style.display=i==cursel?"block":"none";
 	}
}

/*------------------------------��ҳ��-�˵�------------------------*/
function hdnav(){
	var navlen=getId("nav-link").getElementsByTagName("li");
	for (i=2;i<=navlen.length ;i++ )
	{
        getId("nav-link-"+i).className=" ";
		getId("sub-nav-"+i).style.display="none";
	}
}
function shownav(num){
	hdnav();
	getId("sub-nav-"+num).style.display="block";
    getId("nav-link-"+num).className="now-nav";
}