function openPopup(pagina) {
		var w = 850;
		var h = 500;
		var lado = (screen.width - w) / 2;
		var topo = (screen.height - h) / 2;

		window.open(pagina,'_blank', 'width='+w+',height='+h+',top='+topo+',left='+lado+',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no,copyhistory=no');
		
	}