function popup(rel_url)
{
    var width = 500;
    var height = 450;
    var w_offset = 30;
    var h_offset = 30;
    var location = 'top=' + h_offset + ',left=' + w_offset + ',';

    if (screen.width) {
        location = 'top=' + h_offset + ',left=' + (screen.width - (width + w_offset)) + ',';
    }
    var features = 'width=' + width + ',height=' + height + ',' + location + 'resizable=no,scrollbars=yes,toolbar=no,location=no,menubar=no,status=no';
    var popupWin = window.open(rel_url, '_popup', features);
    popupWin.focus();
}