<div class="row">
    <div class="col-xs-12 col-sm-12 col-md-6 col-lg-6">
        <?php
        include __DIR__ . '/mytasks.php';
        ?>
    </div>
    <div class="col-xs-12 col-sm-12 col-md-6 col-lg-6">
        <?php
        include __DIR__ . '/messages.php';
        ?>
    </div>
</div>