s_width=screen.width;
s_height=screen.height;
w_width=s_width/2;
w_height=s_height/2;
w_top=(s_height-w_height)/2;
w_left=(s_width-w_width)/2;
function apri(pag){
options     = 'toolbar=yes,width='+w_width+',height='+w_height+',top='+w_top+', left='+w_left+',directories=no,status=yes,menubar=no,scrollbars=yes,resizable=yes,caption=yes'
win=window.open(pag,'LinksEsterni',options);
}