function popup(url)
{
    win = window.open(url, "popup", "width=500, height=300, directories=no, location=no, menubar=no, scrollbars=no, status=no, titlebar=no, toolbar=no, resizable=yes");
    return (typeof(win) == 'object') ? true : false;
}

function pre_view(url)
{
    dst = document.getElementById('preview');

    if (!dst) {
        //alert('preview error');
        return;
    }

    if (url == 'empty.jpg') {
        dst.style.visibility = 'hidden';
    } else {
        img = '/rs/eshop_zbozi/upload/img_small/' + url;
        dst.style.visibility = 'visible';
        dst.src = img;
    }
}