<div class="row">
    <div class="col-xs-12 col-sm-6 col-md-4 col-lg-4 col-sm-offset-3 col-md-offset-4 col-lg-offset-4">
        <div class="alert alert-warning"><b><?php lang("404 error");?></b><br /> <?php lang("page not found"); ?></div>
    </div>
</div>