function nov_tab(top,con,a,j){
	
	//alert(top+"บอ"+con+"บอ"+a)
	    for (var i=0;i<j;i++){
			  document.getElementById(con+i).style.display="none";
			  document.getElementById(con+a).style.display="block";
			  document.getElementById(top+i).className="";
			  document.getElementById(top+a).className="current";
		}
	}