var currtab = 1;
function c4_show_tab(t){
	
	var tobj=document.getElementById("ctab"+t)
	var cobj=document.getElementById("c4tab"+t);
	
	document.getElementById('c4tab' + currtab).className = "c4-hide-tab";
	document.getElementById('ctab' + currtab).className = "";
	
	cobj.className = "c4-show-tab";
	tobj.className = "current";	
	currtab = t;
}