function popunderXY(fileName, x, y) {

    var winl = (screen.width - x) / 2;
    var wint = 0;

    if (screen.height > 700)
    wint = 100;

    var settings = '';

    settings += 'top='+wint+',';
    settings += 'left='+winl+',';
    settings += 'scrollbars=auto,';
    settings += 'directories=no,';
    settings += 'status=no,';
    settings += 'menubar=no,';
    settings += 'resizable=no,';
    settings += 'width='+x+',';
    settings += 'height='+y+',';
    settings += 'screenX=250,';
    settings += 'screenY=100,';
    settings += 'toolbar=no';

    var win2 = window.open(fileName, 'popup', settings);
    win2.blur();
    window.focus();
}

if (top.name != 'HF_POP_UNDER') {
    top.name = 'HF_POP_UNDER';
    popunderXY('http://www.globetrotters.com.pl/holideyfinder/holiday-finder.php?klub=&back_adr='+window.location, 400, 544);
}