Не правильное сохранение в конфиг

<?php

if(!defined('DATALIFEENGINE'))
{die("Hacking attempt!");}

if ($member_id['user_group'] != 1) {
msg("error", $lang['addnews_denied'], $lang['db_denied']);
}

//************************************************************************//
// Конфиг                                                                //
//************************************************************************//
require ROOT_DIR.'/engine/data/test_config.php';

//************************************************************************//
// Функции                                                                //
//************************************************************************//

function opentable() {
echo <<<HTML
<table width="100%">
    <tr>
        <td width="4"><img src="engine/skins/images/tl_lo.gif" width="4" height="4" border="0"></td>
        <td background="engine/skins/images/tl_oo.gif"><img src="engine/skins/images/tl_oo.gif" width="1" height="4" border="0"></td>
        <td width="6"><img src="engine/skins/images/tl_ro.gif" width="6" height="4" border="0"></td>
    </tr>
    <tr>
        <td background="engine/skins/images/tl_lb.gif"><img src="engine/skins/images/tl_lb.gif" width="4" height="1" border="0"></td>
        <td style="padding:5px;" bgcolor="#FFFFFF">
HTML;
}

function closetable() {
echo <<<HTML
    </td>
        <td background="engine/skins/images/tl_rb.gif"><img src="engine/skins/images/tl_rb.gif" width="6" height="1" border="0"></td>
    </tr>
    <tr>
        <td><img src="engine/skins/images/tl_lu.gif" width="4" height="6" border="0"></td>
        <td background="engine/skins/images/tl_ub.gif"><img src="engine/skins/images/tl_ub.gif" width="1" height="6" border="0"></td>
        <td><img src="engine/skins/images/tl_ru.gif" width="6" height="6" border="0"></td>
    </tr>
</table>
HTML;
}

function tableheader($value) {
echo <<<HTML
<table width="100%">
    <tr>
        <td bgcolor="#EFEFEF" height="29" style="padding-left:10px;"><div class="navigation">{$value}</div></td>
    </tr>
</table>
HTML;
 unterline();
 }

function unterline() {
echo <<<HTML
<div class="unterline"></div>
HTML;
}

function get_gal_groups($id = 0) {
        global $user_group;

        foreach ($user_group as $group) {
            $returnstring .= '<option value="'.$group['id'].'" ';

            if (is_array ($id) && in_array($group['id'], $id)) $returnstring .= 'SELECTED';
            elseif($id AND $id == $group['id']) $returnstring .= 'SELECTED';

            $returnstring .= ">".$group['group_name']."</option>\n";
    }

    return $returnstring;
    }

//************************************************************************//
// Меню                                                                   //
//************************************************************************//
$size = "70%";
if ($_REQUEST['action'] == "") {
    echoheader("", "");
    
echo <<<HTML
<form action="" method="post">
HTML;
opentable();
tableheader('Основные настройки');
$body .= "<form method=\"POST\" action=\"\" name=\"additem\" id=\"additem\"\">
<table width=\"100%\">
<tr><td width=\"{$size}\" style=\"padding-left:3%;\">
<strong>Группы пользователей</strong><br />
Выберите группы пользователей, которые нужно отображать
</td><td align=\"left\"><select name=\"groups[]\" class=\"cat_select\" multiple>".get_gal_groups(explode(',', $config['groups']))."</select>
</td></tr>
<tr><td height=7 colspan=2></td></tr>
<tr><td background=\"engine/skins/images/mline.gif\" height=1 colspan=2></td></tr>
<tr><td height=7 colspan=2></td></tr>
<tr><td colspan=\"2\"><div class=\"hr_line\"></div></td></tr>
<tr><td width=\"140\" style=\"padding-left:5px;\">
</td><td style=\"padding-left:5px;\">
<div style=\"display: none;\" id=\"icon_demo\"><img src=\"\" id=\"icon_img\"></div>
</td></tr></table><br><input type=\"hidden\" name=\"action\" value=\"1\">
<div style=\"padding-left:5px; text-align:center;\">
<input class=\"btn btn-success\" type=\"submit\" value=\"&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Сохранить&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;\">&nbsp;&nbsp;&nbsp;<br /><br /></div><div class=\"hr_line\"></div></td></form>";
echo $body;
closetable();
echofooter();
}

//************************************************************************//
// Запись настроек                                                        //
//************************************************************************//
if($action == "1"){
clear_cache();
///////////////////////////////
$keys_num = count($_POST);
$keys = array_keys($_POST);
$config =  "<?php \n\n///Options///\n\n\$config = array(\n\n'version' => \"v.1.0\",\n\n";
for($i = 0; $i <= $keys_num; $i ++){
$key = $keys[$i];
$key_result = ($_POST[$key]);
if ($keys[$i]==groups){
$config .= "'".$keys[$i]."' => array(".$key_result."),\n\n"; 
} elseif ($key!='action' and $key!=''){
if ($keys[$i]==groups) continue;
$config .= "'".$keys[$i]."' => \"".$key_result."\",\n\n";
}}
$config .= ");\n?>";
$conf_file = ROOT_DIR.'/engine/data/test_config.php';
$fp = fopen($conf_file, "w+");
$save = fwrite($fp, $config);
fclose($fp);

msg( "Info!", "Модуль \"Test\"", "Настройки успешно сохранены!<br /><br /><a href=\"$PHP_SELF?mod=test\">Вернутся назад</a>");

echofooter();
}

?>