function open_popup(pagina, w, h)  {
			var parameters = "width=" + w + ", height=" + h + ", left=100, top=50, toolbar=0, location=0, directories=0, status=0, menubar=0, scrollbars=1, resizable=1";
			var winpopup = window.top.winpopup;
			
			window.top.winpopup = window.open(pagina, '_blank', parameters);
			window.top.winpopup.focus()
		}