function tabClick(fnc){
	for(i =0; i < 4; i++){
		if(document.getElementById('tab0' + i)){
			document.getElementById('tab0' + i).style.visibility = "hidden";
		}
	}
	document.getElementById('tab0' + fnc).style.visibility = "visible";

	if(fnc == 1){
		document.getElementById('topics').style.overflow  = "auto";
	}else{
		document.getElementById('topics').style.overflow  = "hidden";
	}
}