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=yes, status=yes, toolbar='+tool
	win = window.open(pagina,nomewindow,settings)
 }