function showPopup(image, name)
{
    html =  '<html>';
    html += '<head><title>' + name + '</title></head>';
    html += '<body leftmargin=0 marginwidth=0 topmargin=0 marginheight=0>';
    html += '<center>';
    html += '<img src="http://' + document.domain + image + '" border=0 name=image style="padding: 0 10px 0 10px;" onload="window.resizeTo(document.image.width + 80,document.image.height + 100)">';
    html += '</center>';
    html += '<p style="text-align: center;">';
    html += '<a href="#" onclick="javascript: window.close();" style="display: block; background-color: #00b7ce; color: #ffffff; text-align: center; font-weight: bold; text-decoration: none; font-family: arial; font-size: 12px;line-height: 23px;">sluit dit venster</a>';
    html += '</p>';
    html += '</body>';
    html += '</html>';

    popup=window.open('','','toolbar=0,location=0,directories=0,status=no,menuBar=0,scrollbars=0,resizable=1');
    popup.document.open();
    popup.document.write(html);
    popup.focus();
    popup.document.close();

    return false;
}

function checkSubscription()
{
    var obj_regexp = /^[A-Za-z0-9](([_\.\-]?[a-zA-Z0-9]+)*)@([A-Za-z0-9]+)(([\.\-]?[a-zA-Z0-9]+)*)\.([A-Za-z]{2,})$/; /* Email adres */

    obj_email = document.getElementById('email');
    if (!obj_regexp.test(obj_email.value))
    {
        alert('Er is geen juist e-mail adres ingevuld.');
        obj_email.focus();
        return false;
    }

    obj_opt1 = document.getElementById('aanmelden_y');
    obj_opt2 = document.getElementById('aanmelden_n');

    if (obj_opt1.checked == false && obj_opt2.checked == false)
    {
        alert('Wilt u zich aan of afmelden?.');
        obj_opt1.focus();
        return false;
    }
}