function makeactive(tab) { 
	document.getElementById("tab0").className = "";
	document.getElementById("tab1").className = ""; 
	document.getElementById("tab2").className = ""; 
	document.getElementById("tab3").className = ""; 
	document.getElementById("tab4").className = ""; 
	document.getElementById("tab5").className = ""; 
	document.getElementById("tab6").className = ""; 
	document.getElementById("tab7").className = ""; 
	document.getElementById("tab8").className = ""; 
	document.getElementById("tab9").className = ""; 
	document.getElementById("tab10").className = ""; 
	document.getElementById("tab11").className = ""; 
	document.getElementById("tab12").className = "";
	document.getElementById("tab"+tab).className = "active";

}