function popup (url,w,h,scrollbars,nuovo) { 
            var t,l;
					t=-20+(screen.height-h)/2;
					l=(screen.width-w)/2;
					if (nuovo=="")
					nuovo='popup';
					if (scrollbars==true){ popname=window.open(url, nuovo, 'menubar=no,toolbar=no,location=no,directories=no,scrollbars=yes,resizable=no,top=no,copyhistory=no,width='+w+',height='+h+',top='+t+',left='+l+',screenX='+l+',screenY='+t); }
					else { popname=window.open(url, nuovo, 'menubar=no,toolbar=no,location=no,directories=no,scrollbars=no,resizable=no,top=no,copyhistory=no,width='+w+',height='+h+',top='+t+',left='+l+',screenX='+l+',screenY='+t);	}
				}