function changeNav(obj){
	id2=obj.id.split("_")[2]
		//alert(id2)
		var tabs = document.getElementById("subnav").getElementsByTagName("li");
		for(var i=1;i<tabs.length-1;i++){
			tabs[i].style.display="none";		
			}
		for(var j=1;j<tabs.length-1;j++){
			var n=tabs[j].id.split("_")[1]
			if(n==id2){
				tabs[j].style.display="block";	
				if (tabs[j].innerHTML=="")
			{
				document.getElementById("subnav_l").style.display="none";
				document.getElementById("subnav_r").style.display="none";
				tabs[j].style.display="none";
			}else
				{
				document.getElementById("subnav_l").style.display="block";
				document.getElementById("subnav_r").style.display="block";
			}
			}

		}
		var tabnav=document.getElementById("nav").getElementsByTagName("li");
		for (var i=0;i<tabnav.length;i++ )
		{//alert(tabnav[i].id)
		if (tabnav[i].id!="m_l"&&tabnav[i].id!="m_r")
		{			tabnav[i].style.backgroundImage="url(images/nav_c.gif)";

		}
		obj.parentNode.style.backgroundImage="url(images/nav_s.gif)";
		}
		var subnavul = document.getElementById("subnavul")
		subnavul.style.marginLeft=eval(id2+"*40")+"px";
	}