<!-- apre popup al centro -->

		function MM_openBrWindow(theURL,winName,features) { 
		  window.open(theURL,winName,features);
		}
		
		function popup(pagina,nomewindow,w,h,scroll,tool)
			 {
				LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
				TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
				settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable=no,status=no,toolbar='+tool
				win = window.open(pagina,nomewindow,settings);
			 }