function openPopupWindow(url, width, height, hasScrollbars)
		{
		//	var features = 'location=no,menubar=no,status=no';
			var features = 'toolbar=no, location=no,directories=no,status=no,menubar=no,resizable=yes';
			if (hasScrollbars)
				features+= ',scrollbars=yes';
			else
				features+= ',scrollbars=no';
			
			if (width > 0 && height > 0)
			{
				features += ',width=' + width;
				features += ',height=' + height;
				features += ',left=' + ((window.screen.width-width)/2);
				features += ',top=' + ((window.screen.height-height)/2);
			}
			return window.open(url, '_blank', features);
		}
		var winpop = null;
		function abrirVentana()
		{
			//130 es el ancho, y 210 es el alto.
			winpop = openPopupWindow('pop.html','125','200');
		}
		function cerrarVentana()
		{
			if (winpop != null)
				winpop.close();
		}