function openDate() 
{
    var width  = 200;
    var height = 180;
    x = (640 - width)/2, y = (480 - height)/2;

    if (screen) {
        y = (screen.availHeight - height)/2;
        x = (screen.availWidth - width)/2;
    }

    inserisciData = window.open('SelezionaData.html','data','width='+width+',height='+height+',screenX='+x+',screenY='+y+',top='+y+',left='+x+',titlebar=no');
}