function abrirJanela(mypage, myname, w, h) {
		var winl = (screen.width - w) / 2;
		var wint = (screen.height - h) / 2;
		winprops = 'height='+h+',width='+w+',top='+wint+',left='+winl+', toolbar=no, location=no, directories=no, status=yes, menubar=no, scrollbars=yes, resizable=no, menubar=no';
		window.open(mypage, myname, winprops);
	}