function arr_recurse_clean($arr) {
    foreach ($arr as $key => $value) {
        if (is_array($value)) {
            $arr[$key] = arr_recurse_clean($value);
        } else {
            $arr[$key] = mysql_escape_string($value);
        } 
    }
    
    return $arr;
}

$_GET = arr_recurse_clean($_GET);
$_POST = arr_recurse_clean($_POST);